New species of Geissorhiza ( Iridaceae : Crocoideae ) from the southern African winter rainfall zone , range extensions , taxonomic changes , and notes on pollen morphology and floral ecology

Field work during the past 15 years has resulted in the discovery o f 12 new species o f the western southern African genus Geissorhiza Ker Gaw l. and range extensions for several more. Follow ing a survey o f pollen morphology in the genus, we describe new pollen types in one section each o f the two subgenera: five species o f section Ciliatae Goldblatt and two o f section Weihea Eckl. ex Baker have more complex apertures than the plesiomorphic single aperture with a 2-banded oper­ culum found in other species. In addition, populations currently referred to the typical white (cream)-flowered G. inflexa (D.Delaroche) Goldblatt with larger, pink, red or purple flowers, have a third pollen type and are recognized as G. erosa (Salisb.) R.C.Foster. The new species are G. altimontana from the high Langeberg near Grootvadersbos; G. helmei from the Piketberg; G. lupidosa from the Du Toits Kloof Mtns; G. monticola from the Swartberg; G. platystigma from Darling, north o f Cape Town; G. sufHava from the Piketberg; G. tricolor from Riversdale (all subgenus Weihea ( Eckl. ex Baker) Goldblatt); and G. cantharophila from the Klein Roggeveld; G. demissa from the Kamiesberg. Gitberg and Cold Bokkeveld; G. exilis from the Waaihoek Mtns in the Worcester District; G. reclinata from the Swartberg: and G. saxicola from the northern Cedarberg-Pakhuis Mountain complex (all subgenus Geissorhiza). We also report range extensions and provide morphological notes for several species, including G. monanthos Eckl.. new collections o f w hich show that the inclusion o f G. leu isiae R.C.Foster in that species was incorrect and we resurrect the species. The addition o f 12 new species and recognition o f G. erosa and G. lewisiae bring to 99 the number o f species in the genus. New identification keys for Geissorhiza are provided that include all new species. We have also accumulated observations o f floral ecology in the genus and integrate them with what is known about this aspect o f the biology o f Geissorhiza. Unusual strategies include deceptive pollination in G. tulhaghensis F.Bolus by tabanid flies and in two species, pollination using empid flies in combination w ith halictid bees.


INTRODUCTION
Geissorhiza Ker Gawl., now with 99 species, is a large genus o f Iridaceae subfamily Crocoideae Bur nett centred in the southern African winter rainfall zone (Goldblatt 1985;Goldblatt & Manning 2000a;Manning et al. 2002) and largely confined to the Cape floristic region (as defined by Goldblatt & Manning 2000a).Field work conducted in the decade since the publication of the last revision o f the genus (Goldblatt 1985) resulted in the discovery and collection o f four new species (Gold blatt 1989;Goldblatt & Manning 1995a).increasing to 85 the number o f known species.Further novelties that have accumulated since then include seven species of subgenus Weihea (Eckl.ex Baker) Goldblatt and five of subgenus Geissorhiza.
In addition, our knowledge o f the pollen m orphol ogy of Geissorhiza has been expanded as a result o f exam ination o f pollen grains carried by insects cap tured after visiting Geissorhiza species (G oldblatt & M anning 2000b, 2007).W hile m onosulcate grains with a 2-banded operculum are typical o f C rocoi deae (Goldblatt et al. 1991) and also o f Geissorhiza, the two species G. heterostvla L.Bolus and G. inflexa (D.D elaroche) Ker Gawl.(both subgenus Geissorhiza section Ciliatae Goldblatt) were found to have pol len grains that depart from the norm in the genus and subfamily.Instead o f the single, elliptic aperture, these species have a more complex condition with m ultiple apertures, described in detail below.Discovery o f these striking pollen grains led us to examine a range o f spe cies o f the genus.Most species o f subgenus Weihea that we examined have normal grains w ith a 2-banded operculum as do species o f subgenus Geissorhiza.However, four new species.G. cantharophila, G. exi lis, G. saxicola and G. reclinata (all section Ciliatae), as well as G. hracteata and G. nana (section Weihea) have grains with complex, multiple apertures.Fur thermore.the large-flow ered populations o f G. inflexa (sensu Goldblatt 1985).often w ith a pink, red or purple perianth, have a different pollen type from those w ith smaller, white flowers, indicating that they constitute a separate genetic race.For the most part these popu lations are readily separated from typical G. inflexa based on morphology as well as pollen type, and we recognize these plants as a separate species.G. erosa.
We also include range extensions and m orphological notes for G. arenicola, G. Jivaricata.G. heterostvla and G. tenella.With the 12 new species described here and the resurrection o f G. erosa.Geissorhiza now com prises 99 species, all occurring w ithin the Greater Cape Floristic Region (sensu Bom et al. 2006) w ith only G. hracteata extending outside its confines.We provide new keys to the two subgenera o f Geissorhiza (A ppen dix 1).w hich accom m odate all species described since the publication o f the last revision o f the genus (G old blatt 1985).The classification o f the genus and renum bering o f the species is presented in Table 1.
Lastly, we review what little is known about the tloral ecology o f Geissorhiza and present a range o f observa tions on pollinator visits and nectar characteristics o f sev eral species.Available information shows that pollination in the genus is dominated by female bees o f the families Andrenidae, Colletidae.Halictidae and Melittidae plus workers of Apis mellifera (Apidae), often in combination with hopliine scarab beetles, short-proboscid Tabanidae and butterflies.The specialized pollination system using one or more species of long-proboscid Nemestrinidae and Tabanidae is the second most important system in Geis sorhiza, confirmed for five species and inferred for three more.Pollination primarily by hopliine scarab beetles is rare, and is reported for the first time in the genus, as are visits by empidid tlies (Empididae), and also deceptive pollination by short-proboscid Tabanidae.

MATERIALS AND METHODS
Pollen grains obtained from fresh flowers or from her barium specimens o f a range o f species (Table 2) were extracted from anthers with a needle moistened in Calberla's fluid (Ogden et al. 1974) and mounted on glass slides in a drop o f the same fluid.Preparations were examined after 2-24 hours, by which time the exine is stained a darker colour than the aperture and grain con tents.Only two species o f the genus were included in a previous survey o f pollen types in Crocoideae (Goldblatt et al. 1991).Thus, in an effort to determine the extent o f the variation in pollen morphology in the genus, we have surveyed a wide range o f species belonging to both subgenera and all sections (Table 1).
For pollinator observations, insects visiting flowers and seen to contact anthers or stigmatic surfaces were captured and killed using ethyl acetate fumes follow ing methods described by Goldblatt et al. (2004a) and Goldblatt & Manning (2007).The identity o f pollen car ried by captured insects was determined by microscopic examination o f samples removed from their bodies using dissecting needles in the same way as described above for sampling from herbarium specimens.

POLLEN MORPHOLGY
Our survey o f pollen morphology establishes the pres ence of the plesiomorphic type pollen grains reported in our earlier survey o f Crocoideae (Goldblatt et al. 1991) as the most common type in the genus (Table 2).These grains are monosulcate with tectate-perforate exine bear ing small supratectal spinules.The sulcus field is largely smooth apart from a pair o f narrow exine bands (elon gated opercula), lying parallel to one another along the long axis o f the aperture (Figure 1 A).Often there is also a sprinkling o f exine material lying in the centre o f the three apertural zones defined by the opercular bands.
One species o f subgenus Weihea, G. parva.has poorly developed operculum bands, represented merely by two sparsely beaded lines o f exine.
Two species o f subgenus Weihea.among those exam ined.and four of subgenus Geissorhiza have grains o f remarkably different appearance (Table 2).In contrast to the majority ot species in the genus, Geissorhiza can tharophila, G. ex i I is.G. inflexa, G. reclinata.G. saxi cola and most populations o f G. heterostvla (subgenus Geissorhiza section Ciliatae) and G. hracteata and G. nana (subgenus Weihea section Weihea) have grains that depart radically from the standard type.Grains have typical tectate-perforate exine.but have more complex apertures.The ± orbicular and slightly larger grains o f G. hracteata.G. cantharophila.G. nana and some popu lations o f G. heterostvla have two discrete apertures, a smaller elliptic one surrounded by a broad band o f exine (? or operculum) lying within a larger ± elliptic or cir cumferential sulcus (Figure IB).We interpret this grain as derived from the basic type in which the two bands o f the operculum have become wider and longer and their ends have fused, leav ing an island o f enclosed apertural membrane within the operculum.The aperture surrounding this structure may also be elliptic or con tinuous around the grain, leaving the non-apertural part o f the grain as two separate pieces o f exine.Curiously, six populations o f G. heterostyla examined (Table 2), all from the north o f its range, have normal grains with a 2-banded operculum.We have re-examined these col lections and find no taxonomically significant difference between them and the more common G. heterosty la.One o f the collections with normal type pollen grains (Gold blatt 6216 MO) even consists o f the mixture o f shortand long-styled plants that is currently understood to be unique to this species.Some populations o f Geissorhiza inflexa have G. heterostyla-type grains (Figure IB; Table 2) but in others the grains have five or six bands o f exine running across the grain separated by apertures o f about the same width (Figure 1C).The bands merge at one pole so that in this view five or six elliptic zones o f apertural membrane are visible, whereas viewed at right angles, the apertures run the length o f the grain separated by long bands ot exine.At the opposite end the exine bands do not quite fuse but adjacent bands fuse toward their tips.All the large-flowered populations o f G. inflexa, with either red, pink, purple or white flowers have this apertural pattern.These large-flowered colour morphs were included in G. inflexa by Goldblatt (1985) without infraspecific rec ognition.
A last v ariant is the plant described here as Geissorhiza reclinata.which has pollen grains w ith two large horse- Pollen grains with a 2-banded operculum are not uni versal in Crocoideae but are the only type known in 16 of the 29 genera recognized in the subfamily (Goldblatt et al. 1991) (Goldblatt et al. 2004b); 4. Savannosiphon.which has polyaperturate pollen grains (Goldblatt et al. 1991); 5, Afrocrocus, which has trizonosulculate grains; and 6.Micranthus, which has zonosulcate grains with the exine reticulate except close to the aperture where the sculptur ing grades from microreticulate to perforate immediately adjacent to the aperture margin (Goldblatt et al. 1991. and unpublished data).
The discovery o f unusual pollen grains in two spe cies o f section Weihea o f subgenus Weihea and several of section Ciliatae o f subgenus Geissorhiza represents another significant departure from the standard type in Crocoideae and a striking specialization within the genus.The presence o f divergent pollen types in Geis sorhiza is most parsimoniously viewed as evidence for a close relationship o f the species o f each subgenus that share the character even though the precise mor phology of the apertures may differ.G. heterostyla and G. inflexa are already believed to be closely related on account of their similar, derived leaf blades (Goldblatt 1985), and G. exilis shares a similar vegetative morphol ogy (Goldblatt 1985).A fourth species with this pollen type.G. cantharophila, until now included in G. hetero styla, is obviously immediately related to that species.
The appearance of normal-type pollen grains in the six northernmost populations sampled o f G. heterostyla (Langberg to Hantamsberg and Bokkeveld Mountains) is surprising.No feature sets them apart in the genus and all that can be concluded at present is that the variation has a geographic component.Variation in pollen grain morphology within a species is surprising since pollen and seed morphology are widely believed to be highly conservative.Variation even within a genus on such a scale as reported here is unexpected.In section Weihea.G. hracteata and G. nana share similar divergent pol len grains, which supports Goldblatt*s (1985) inference based on morphology that they are immediately allied.
The broader significance of the divergent pollen grains is uncertain.None o f the species seem particularly unusual morphologically in Geissorhiza.Two o f them, G. inflexa and G. heterostyla have w hat may be termed a generalist pollination system that includes female bees and Apis mellifera workers, hopliine beetles, and occasionally butterflies, a pattern encountered widely in Geissorhiza (see below ).Geissorhiza cantharophila is adapted for pollination by hopliines.three species of w hich have been captured on the flowers.
Another issue concerns the significance at the taxo nomic level o f the grains o f the large-flow ered 'Geis sorhiza erosa' populations o f G. inflexa, which have 5 (or 6) apertures.The justification for the reduction o f this taxon in G. inflexa by Goldblatt (1985) was the pres ence in G. inflexa sensu lato o f populations w ith larger than usual, pink or purple flowers that seemed to link the typical and common form o f G. inflexa, which has mod erate-sized.white flowers, with the large-flowered G. erosa w ith its brilliant scarlet perianth.In the light o f the consistent association o f this different pollen w ith large, white, pink or red-flowered plants we conclude that the larger-flowered plants constitute a separate genetic race and we re-evaluate their taxonomic status below.

SYSTEM ATICS
The new species are arranged numerically w ithin sub genera.Their position and number in the classification o f Geissorhiza is given in Table 1.
Eponymy: from the Latin, tricolor, three-coloured, for the golden yellow flower with a maroon central eye and pale yellow in the throat and tube.
Distribution and ecology: known from just one col lection on Leeuriviersberg (Grootberg) west o f Swellendam.Geissorhiza altimontana occurs at high elevations in the Langeberg at ± 1 550 m (Figure 3).Plants were collected in unbumed veld, growing on damp, mossy ledges on steep, south-trending slopes.The area is exposed to frequent summer cloud from southeast trade w inds, making flowering o f this soft geophyte possible in a region o f predominantly summer drought.
Distribution and ecology*: the only know n population of Geissorhiza monticola is from the central Swartberg, west of Swartberg Pass (Figure 3).Plants grow on south-trend ing, rocky sandstone slopes in pockets of peaty sand.flowers that are held upright, with elliptical or obovate, pale mauve tepals mostly 7-10 mm long, erect stamens w ith fil aments 3-5 mm long, and a central style of similar length w ith short style branches up to 1.5 mm long, thus less than half as long as in G. monticola.Geissorhiza nigromontana may also be confused with G. monticola but it has a stem ± prostrate toward the base, a spike of 2 or 3 flowers (flowers always in G. monticola), bears cormlets in the leaf axils, shorter leaves with blades 4-10 mm wide (vs 2-3 mm in G. monticola) and the flowers are, as far as known (Gold blatt 1985), upright and radially symmetric.
The flow ers o f Geissorhiza monticola bear a remarkable similarity to those of G. grandiflora in their orientation, shape, and in the well-exserted.declinate stamens and style but this similarity is presumably due to convergence.G. grandiflora from the southwestern coastal mountains has leaves w ith prominently thickened margins and main vein, and is thus 2-grooved on each surface, has (l-)3-8-flowered spikes, and longer floral tubes.10-22 mm long.
Eponymy: from the Latin, lapidosus, stony or rocky, for the habitat.
Distribution and ecology: known from two small colo nies below the shale band on Goudini Sneeukop in the Du Toitskloof Mtns (Figure 3).Plants are localized along a narrow band o f sandstone pavement at the edge of cliffs where they occur in moist seepages draining from a shale sponge overlying the sandstone, a very restricted habitat less than 4 m wide, where the shale band meets the under lying sandstone.The two colonies seen are about 800 m apart.The area regularly has a snow cover in winter and spring.
Diagnosis and relationships: the oblique corm with concentric tunics and smooth.± plane, falcate leaves with the uppermost clearly cauline, place the dwarf Geis sorhiza lapidosa in section Weihea of subgenus Weihea.
It is distinguished from similar small species of the sec tion by its high montane habit and unusual leathery, fal cate leaves at most 1 mm wide.Particularly distinctive are the short-tubed, white flowers with the outer tepals flushed reddish pink and the short style, which branches opposite the lower half o f the anthers.The style is eccentric, typi cal of the genus, as are the recurved style branches, ± 2 mm long.Similar, bicoloured flowers are found in G. nana and G. setifolia, both lowland species: G. nana occurs in renosterveld vegetation in the Overberg between Caledon and Riversdale and has broader, thin-textured leaves 1-2 mm wide and even smaller flowers with the tepals mostly 3-6 mm long, and very short stamens with filaments ± 2 mm long; G. setifolia grows in seasonally wet places on flat sandy or loamy ground in Western Cape between Gouda and Caledon and has similarly narrow but linear leaves, 0.5-1 (-2) mm wide but larger flowers with tepals 6-8 mm long, a longer tube ± 6 mm long, and the style branching at the tips of the anthers.Other similar species in the group have plain white, mauve or purple flowers and generally broader leaves.Goldblatt & J.C.Man ning, sp. nov.Plantae 25-50 mm altae, cormo campanulato basi ad marginem dentato ± 3 mm diam., foliis linearibus ± 1 mm latis, caule usitate prope basin 1-vel 2-ramoso, floribus actinomorphis flavis, tubo perianthii ± 1.5 mm longo infundibuliformi, tepalis anguste ovatis 6-7 x ± 3 mm, filamentis ± 2 mm longis, antheris ± 1.5 mm longis, ramis styli ± 1.5 mm longis prominenter villosis.
Eponymy: from the Latin, sufflavus, the pale yellow colour o f the tepals.

Diagnosis and relationships
Diagnosis and relationships: in its general aspect Geis sorhiza helmci recalls species o f section Engysiphon (G.J.Lewis) Goldblatt o f the genus, all members o f which have fairly large corms with concentric tunics, the fragments o f which taper above into short bristles.and a single long basal leaf, always with thickened and winged margins and central vein, and with the surface o f the margins glandular and with sand adhering to them (Goldblatt 1985).Most other members o f this alliance have flowers with a longer perianth tube, but at least G. brevituba (G.J.Lewis) Goldblatt has a short tube.± 8 mm long, thus comparable to the tube o f G. helmei; however.G. brevituba.also restricted to the Piketberg.has larger flowers with tepals 25-30 mm long.The spike o f this species typically has only 1 to 3 flowers, the stamens and style o f which are unilateral and declinate, w ith the style dividing well beyond the anther tips.
Leaves 4. low er two basal, third leaf inserted shortly above ground, blades linear-falcate, reaching to about base of spike.0.7-1.0mm wide, margins and central vein lightly thickened and narrowly w inged, glabrous, uppermost leaf cauline.largely to entirely sheathing.Spike 1-or 2-flowered: bracts green below, dry and brow n in upper half to two thirds, outer ± 5 mm long, inner ± 4 mm long.Flow ers actinomorphic.w hite w ith veins tinged blue below and rev erse of outer tepals flushed blue in distal half: perianth tube funnel-shaped.± 2 mm long: tepals subequal, obov ate.
Ovary with style slender, short, ± 3 mm long, dividing opposite lower third o f filaments, style branches ascend ing, slightly outcurved, ± 3 mm long, extending between lower third o f anthers.Capsules subglobose, 3-lobed, 6 -7 mm long.Seeds tetrahedral, colliculate, ± 2 mm long.Flowering time: late August to mid September, occa sionally lasting until early October; flowers opening late morning and closing in late afternoon.Figure 12.

Distribution and ecologyn Geissorhiza cantharophila
is restricted to Klein Roggeveld and nearby (Figure 8) and is most often found on south-trending slopes or flat ground on shale and clay.In years o f ample rainfall, as in 2006, plants can be so common that in flower they colour the veld with a haze o f pink for many kilometres.
Diagnosis and relationships: the blackish corm tunics with overlapping layers that split regularly along the lower margin, place Geissorhiza cantharophila in sub genus Geissorhiza.The two basal leaves have broadly winged margins and a raised and winged central vein exactly like those o f its presumed immediate relatives, G. inflexa and G. heterostyla, and it also has the derived pollen grains with complex aperture and operculum char acteristic o f its two relatives and their immediate allies.So alike are the three species that they can be distin guished only with difficulty in the herbarium.Seen alive, however, the glistening mauve-pink to purple flowers with a dark purple centre, purple filaments and a short purple style o f G. cantharophila are unmistakable.The style, ± 3 mm long and dividing opposite the lower third o f the filaments, and the almost straight style branches are unique in the subgenus and we infer that they are associated with its pollination system.The upright flow ers are adapted for pollination by hopliine beetles, two or more species o f which have been found on the flowers on warm sunny days.The short style results in the place ment o f the style branches at exactly the right level to brush against a beetle's body as it crawls across the peri anth.A longer style, such as found in its relatives, would place the style branches beyond the level o f a beetle visi tor.Hopliine beetles captured in the flowers include Anisochelus inornatus, Anisonyx hi laris and A. ignites.
The widespread Geissorhiza heterost\la is vegetatively identical and is particularly difficult to distinguish from G. cantharophila when pressed and dried but alive, the blue to mauve or almost white flowers, pale yellow in the tube with the mouth sometimes edged in darker blue or mauve, and ± white stamens and style branches make it easy to separate the two species.When the flowers of G. heterostyla first open, the spreading tepals are held at ± 30° to the horizontal with the style and anthers unilat eral and lying above the lowermost tepal.As the flower ages, the spike axis becomes straight and the flower is then held upright.In all but a few populations o f the spe cies, the style is relatively long and reaches the top of
Diagnosis and relationships: the dark brown, over lapping corm tunics and unequal filaments place Geis sorhiza reclinata in subgenus Geissorhiza where it seems taxonomically isolated.It keys out in the cur rent rev ision of the genus (Goldblatt 1985) w ith a small group o f southw estern Cape mountain species, including G. pseudinaequalis Goldblatt and G. scopulosa Gold blatt.and like the latter it has sparsely short-hairy stems and leaves w ith the margins and central vein winged, the w ing edges minutely ciliate (at least a 10x lens is needed to see these features).The short perianth tube ± 2 mm long is consistent w ith that o f G. scopulosa but the fairly large flowers w ith tepals ± 15 mm long are much larger than in G. scopulosa.w hich has tepals 8-9 mm long.
Distribution and ecology> : Geissorhiza exilis is known only from the slopes o f the Waaihoek Mtns west o f Worcester, where it grows on fairly steep slopes in sandy ground among sandstone boulders (Figure 8).The single collection was made in the spring following a fire during the previous summer.
Diagnosis and relationships'.Geissorhiza exilis is identified by the narrow, sublinear to falcate leaves with the margins and central vein raised and extended into prominently ciliate wings, combined with a glabrous stem and flowers with equal filaments.Leaf morphology places the species in section Ciliatae (Goldblatt 1985) o f subgenus Geissorhiza where it appears to be most like G. inflexa.This species is an altogether larger plant with corms 7-12 mm diam., leaves mostly at least 3-4 mm wide, and flowers with tepals at least 8 mm long and more often 10-18 mm long.The stamens o f G. inflexa are also larger, the filaments 4 -7 mm long, the anthers mostly 3 -6 mm long, and the style branches 4-5 mm long.Whereas G. inflexa favours clay or loam slopes and flats in renosterveld, G. exilis is a plant o f sandy slopes in fynbos habitats.
We have seen no other collections o f the species but we suspect that it may not be as rare as it appears, for the plants are inconspicuous even when locally common and in full bloom.Difficulty in naming small-flowered species o f Geissorhiza is also likely to discourage col lectors.
Eponymy. from the Latin, saxosa, stony or rocky, and -icola, living in, describing the habitat.
Distribution: Geissorhiza saxicola is known from just three collections from the northern Cedarberg and Pakhuis Mountains east o f Pakhuis Pass (Figure 8).Plants grow in sandy soil, in moist shady sites in the shelter o f sandstone rocks, and may be locally abundant.
Diagnosis and relationships: Geissorhiza saxicola is recognized by the combination o f a papillate-hairy stem, leaves with the margins and central veins winged with pilose wing edges and small, pink flowers with unequal filaments.The immediate relationships o f G. saxicola are uncertain although it clearly falls in section Ciliatae.
Pollen grains are specialized in their complex aperture, which places the species closest to G. exilis and G. infl exa.but in both these species the filaments are equal in length.Although its low stature and small flowers recall G. minuta ot the Gifberg and Pakhuis Mountains, that species has a smooth stem, equal stamens, and the thick ened leaf margins and central vein lack the w ings with ciliate edges of G. saxicola.Geissorhiza leipoldtii is more distantly allied to G. saxicola but although it often has unequal stamens, the flowers are much larger (tepals (13-) 18-28 mm long; anthers 6-8 mm long) and the style divides at or beyond the anther tips.

RANGE EXTENSIONS, MORPHOLOGICAL NOTES AND TAXONOMIC CHANGES
The numbers of the species follow the classification in Table 1.Elsewhere G. arenicola has blue flowers.

Geissorhiza hracteata Klatt
The recorded range for this species is the southern Cape, extending from near Swellendani eastward to Gra-hamstown (Goldblatt 1985).

NBG. PRE).
A second collection from the Voetpadsberg near Touws River (3 October 1999.Goldblatt & Ndnni 11198 MO) in fruit is probably also this species and if cor rectly identified extends the range inland where it has not before been found.The Burgers Pass collection has the derived pollen type, typical of Geissorhiza hracteata but has prostrate leaves, unlike most other collections of the species, and the perianth tube is ± 2.5 mm long.Elsewhere in G. hracteata.the perianth tube is 3-5 mm long.

Geissorhiza divaricata Goldblatt
A small-flowered species.Geissorhiza divaricata (subgenus Geissorhiza) was known from the northern r \ Bokkeveld Mountains and the Gitberg when described (Goldblatt 1985).The slender habit, divaricate branching with the branch about as long as the main axis, tepals ± 10 mm long and the two basal leaves with raised and nar rowly winged, ciliate margins and primary and secondary veins, readily distinguish the species as belonging in sub  (Foster 1941).This specimen is probably not a type in the current sense, but does serve to authenticate the species.Foster regarded Ixia erosa as the earliest valid name for the illegitimate Geissorhiza hirta (Thunb.)Ker Gawl.(the name used for the species by Baker, 1896, in Flora capensis).No types o f the spe cies described by Salisbury in his 1796 publication are known and so the matter has rested.To fix the applica tion o f the name w e have designated a neotype here.

C O M P T O N H E R B
The large-flowered Geissorhiza erosa is vegetatively indistinguishable from G. inflexa, but the spikes usually have fewer flowers, usually 2-4, a perianth tube 1.5-2.0mm long, tepals 18-24 x 8-10 mm and anthers (6-)7-10 mm long.The outer bracts are 18-20 mm long, the inner ± 2 mm shorter.In contrast, typical G. inflexa also has a perianth tube ± 2 mm long, but tepals 10-15 ( -17 ) x 5 -7 mm, and anthers 4 -6 mm long.The outer floral bracts are 10-15 mm long and the inner about 10-12 mm long; generally the bracts o f G. inflexa are dry and brow n at flowering, but in G. erosa the bracts are often green, turning light brown with age.Plants with a large, pink or occasionally white perianth that occur to the south at Villiersdorp and Bot River have, like typical G. erosa, tepals 18-22 mm long and anthers 8-10 mm long.Apart from perianth colour, the two sets o f populations can be distinguished by bract length, tepal size and anther length (Table 3).There appear to be no consistent differ ences in the styles ot the two species.The style generally div ides opposite the level o f the middle to upper third of the anthers and the style branches are 3-4 mm long.
Geographically, Geissorhiza inflexa in the narrow sense extends trom the Piketberg and the Cape Penin sula eastward to Bredasdorp and Swellendam (Figure 14), whereas G. erosa occurs in the Tulbagh Valley and to the south between Villiersdorp and Bot River and near Stellenbosch, thus entirely w ithin the range o f G. inflexa.
In view o f the different pollen morphology now docu-   and Hondeklipbaai populations.We suspect that G. exscapa occurs between these two stations but has not.as yet, been documented.

Geissorhiza heterostyla L.Bolus
The most widespread species o f the genus, Geis sorhiza heterostyla has been recorded from Kubiskou Mountain near Loeriesfontein in the northwest, across the Bokkeveld Escarpment and Roggeveld to the south ern Cape as far east as Port Elizabeth (Goldblatt 1985).We report here a modest range extension from the Langberg, an isolated, flat-topped m assif about 70 km w est o f Loeriesfontein at the southeastern edge o f Namaqualand.Plants are restricted to the summit plateau o f the range, at ± 1 050 m, w here they are common among dolerite rocks in the red clay derived from decomposed dolerite The species occurs there in mountain renosterveld with other typical western Karoo geophytes including among the Iridaceae, Ixia rapunculoides, Moraea bifida and M. tripetala.and Boophone haemanthoides (Amaryllidaceae) (Goldblatt et al. 2008). .By sheer chance we were able to compare liv ing plants in full bloom from Pakhuis Pass with those from the Gifberg in September 2008 and found them to differ in no significant way.The flowers are virtually identical in size with tepals 7-8 mm long and although w hite.as described, the outer tepals o f both the Gifberg and Pakhuis plants are flushed light, or sometimes dark, purple outside, a feature not before recorded.We were also able to confirm that the stamens are equal in length, which was uncertain at the time the 1985 revision o f the genus was published.The habitat in the northern popula tions is the same as at Pakhuis Pass: wet sandstone pave ment in shallow sandy ground.

Geissorhiza monanthos Eckl.
In the 1985 account o f the genus.Geissorhiza lewisiae R.C.Foster was included in the synonymy o f G. monanthos (Goldblatt 1985).Field observations made since 2000 show that this decision was incorrect.Both G. monanthos and G. lewisiae have unilateral stamens and style but the flowers o f G. monanthos have a large pale, translucent centre surrounded by a dark blue to pur ple or red zone, and curved, bicoloured filaments pale in the lower half but dark violet distally (Figure 15A, B).The median filament is always conspicuously shorter than the others.In contrast.G. lewisiae has a dark blueviolet perianth, usually pale yellow-green in the throat, uniformly v iolet filaments w ith little or no curv ature, the median only very slightly shorter than the others, and the anthers are semi-prostrate (Figure 15C We now follow Foster's (1941) Foster: 39 (1941), as G. monantha (Thunb.)Eckl.; Goldblatt: 422 (1985, including G. lewisiae).Ixia monanthos Thunb.: 226 (1811), horn, illeg.non D.Delaroche (1766) (= Sparaxis sp.).Type: South Africa, Cape: exact locality unknown, Thunberg s.n.{Herb.Thunb.975 UPS!, lecto., designated by Goldblatt 1982).

Geissorhiza tenella Goldblatt
Geissorhiza tenella, one o f three species o f Geis sorhiza (all subgenus Weihea section Engysiphon) with leaves H-shaped in section with broadly winged margins held ± at right angles to the blade surface, is a lowland species o f sandy, coastal and near inland habitats.Its recorded range is from Yzerfontein northwest of Darling in the west to De Hoop, near Bredasdorp in the south east.A collection from Skulpiesbaai Reserve, Stilbaai (13 October 2000, De Villiers & Pienaar SKB20 NBG) extends the range some 60 km to the east.Plants o f this collection have a perianth tube 25-30 mm long and tepals 13x2 mm. the shortest and narrowest recorded in the species.Flower dimensions recorded until now for the species are perianth tube (2 0 -)3 0 ^0 (-5 0 ) mm long and tepals 14-23 x 3.0-4.5 mm (Goldblatt 1985).
FLORAL ECOLOGY Vogel (1954). in his touchstone account o f pollination in the southern African flora, predicted (largely based on floral morphology) that Geissorhiza was primarily a bee-pollinated genus.He also inferred that at least G. juncea (thought by him to have flowers open at night) was moth-pollinated and that G. fourcadei, G. ovata, and G. namaquensis were adapted for the syndrome he called phalaenophily, in which he included butterflies and long-proboscid flies.Vogel made no direct pollinator observations in Geissorhiza but knew o f Scott Elliot's (1891) report o f visits to G. aspera (as G. secunda) by bees (two species o f Halictidae and Apis mellifera) and a bee fly (Bombyliidae).Pollination in Geissorhiza has remained among the least known o f any African genus o f Iridaceae (Goldblatt & Manning 2006) and we thus present those observations that we have accumulated over the past 15 years, noting that a more thorough study o f floral ecology o f Geissorhiza is needed.
A study o f pollination at one site, Lions Head.Cape Town (Nánni unpubl. data. 1994 and1995), has shown that four sympatric and ± co-blooming, short-tubed and small-flowered species, G. aspera, G. inflexa, G. juncea and G. pusilla are pollinated predominantly by small bees (mainly Halictidae) but with occasional visits by bee flies (Bombyliidae).Hover flies (Syrphidae) and hopliine beetles were also captured while visiting G. aspera and G. pusilla, and in addition.Braunsapis spp.(Apidae) and honey bees were captured on G. aspera (lowers ( Fable 4).For G. inflexa and G. juncea, halietid bees far outnum bered visits by other insects.The longtubed G. ovata, also present at the I.ions Head site and co-bloom ing, was occasionally visited by halictids but its long tube and ample nectar suggests that these insects are not its legitimate pollinators as they cannot reach the nectar held within the lower part o f the tube.The white and pink flower o f G. ovata com bined w ith the well-developed tube suggest tabanid flies are the legiti mate pollinators but none were seen at the Lions Head site, nor at a second site at Sir Low ry's Pass where we observed open flowers for two consecutive mornings on warm days ideal for pollinator studies.
Experimental pollinations conducted at Lions Head using standard methods for establishing self and cross compatibility showed that Geissorhiza aspera and G. pusilla are self-com patible when pollinated by hand but showed reduced seed-set when not manipulated by hand (in both crosses insect visitors were excluded).In con trast, G. inflexa, G. juncea and G. ovata were sell-incom patible.Attempts to produce interspecific hybrids by hand-crossing consistently failed, whether species from the same or different subgenera are crossed.These results complement a report o f self-com patibility and autogamy in G. corrugata (Goldblatt 1985) and our determination here o f self-compatibility in G. heterostvla, otherwise unknown in the genus.In one respect these results are surprising, for interspecific crosses are readily made in Gladiolus, Sparaxis and Watsonia, all mem bers o f the same subfamily, Crocoideae (Horn 1962;Goldblatt & Manning 1998).Production o f interspecific crosses is, however, possible in Geissorhiza, for there are occasional records o f naturally occurring hybrids in the genus.One o f these is a report o f interspecific hybrids between G. aspera, G. inflexa and G. tulbaghensis (Louhser 2185, 2188 BOL, NBG); another between G. ovata and G. parva (Goldblatt 1985) and a third between G. hrehmii and G. radians at K oelenhof near Stellenbosch (Beyers 80 NBG).The hybrids exhibit various degrees o f inter mediacy between the species involved.
Observations that we have accum ulated since 1998 while studying the pollination o f other genera o f Iridaceae add modestly to this record (Table 4).Species with a short perianth tube (typically 2 -4 mm long) and a radially sym m etric flower, including G. imhricata, G. juncea, G. karooica, G. louisabolusiae and G. ornithog aloides, are pollinated by female bees o f the families Andrenidae, Colletidae and Halictidae and w orker honey bees (Table 4), som etim es in com bination with hopliine beetles or short-proboscid Tabanidae or butterflies.The only pollinator we have seen and captured on pink-flow ered G. foliosa, w hich has a perianth tube ± 5 mm long, was the butterfly, Colias electo.Putative pollinators cap tured on G. heterostvla at different sites included halictid bees {Patellapis spp.), as well as the hopliine beetles, Anisonyx and Anisochelus, and at one site Colias electo alone.Nectar volumes were always small, 0.5 pi or less, sampled in the field using unbagged flowers.N ectar is evidently lacking in G. bracteata, G. foliosa, G. louisa bolusiae and G. tulbaghensis  4).These red-flowered populations thus appear to have a bimodal pollination strategy (sensu M anning & Goldblatt 2005), offering pollen to bees and a large, bril liantly coloured perianth to attract hopbines to a suitable site for assem bly and copulation.
Particularly notable is our observation for Geissorhiza inconspicua and G. ramosa (Table 4), which were actively pollinated by empidid flies (Empis cf.mavitii: Empidideae), small nectar-feeding Diptera ± 5.5 mm long, in combination with small halietid bees (Lasioglossum spp.).Both these species o f Geissorhiza had small w hite flowers at our study site in Tradouw Pass (and both may also have blue flowers).We have been unable to repeat observa tions on additional populations o f either species.We know o f no other published records o f pollination in the family by empidid flies but we confirmed that the flies brushed against stigmatic surfaces and carried dorsal loads o f pol len, exclusively o f G. foliosa and G. ramosa, on their bod ies.Thus at least at the Tradouw Pass site, empidid flies were effective agents for pollen transfer, as were the halictid bees, which were far outnumbered by the empidids.Empidid flies have also been recorded by us on the shorttubed flowers o f Ixia rapunculoides, Sparaxis pillansii and S. tricolor at sites on the Bokkeveld plateau (unpublished observations).The two Sparaxis species are believed to be adapted for hopliine pollination (Goldblatt et al. 2000b) and I. rapunculoides for large anthophorine bee pollina tion (Goldblatt et al. 2000a).
O bservations o f pollination in the strikingly coloured, dark blue, red and white flowers o f the Geissorhiza radi ans group are still unfortunately limited.W'e captured unidentified halietid bees and the horsefly Philoliche a tricorn is on G. ew ystigm a and the bee Andrena sp.(A ndrenidae) and beetle Anisonyx ursus (Scarabaeidae Hopliini) on G. monanthos.Again, these insects carried loads o f pollen o f the host species and w ere seen to brush against stigm atic surfaces.Geissorhiza splendidissima, which has a brilliant blue perianth and brown anthers and pollen, is visited by Apis mellifera and the large Anthophora longipes.
Geissorhiza cantharophila is so far the only species o f the genus shown to be primarily adapted for pollina tion by hopliine beetles.As mentioned above, we cap tured three species o f beetles on flowers o f the species at two different sites, Anisonyx hilaris, A. ignitus and Ani sochelus inornatus (Table 4).We infer the same pollina tion system for G. tricolor because o f its flower pigm en tation: bright yellow with a large dark-brow n central eye.
The purple-flowered form o f G. aspera from M alm es bury also requires mention here.Unlike the blue-violetand white-flowered populations, which have a yellowgreen tube edged in a darker colour, in the M almesbury populations the flowers are purple w ith the filaments and throat dark purple-black.We suspect the population has shifted from a generalist to an exclusively hopliine polli nation system.Anisonvx ursus is sometimes seen on the flowers.Apart from perianth and filament pigmentation, we find no differences w ith typical G. aspera.This unu sual form is threatened today by urban development as new suburbs develop around Malmesbury.
Lastly, the southwestern Cape endemic.Geissorhiza tulhaghensis, which has large, zygomorphic.white flow ers w ith a dark brow n centre, is visited exclusively by the horsefly, Philoliche atricornis, also a common visitor to co-blooming Arctotheca capensis and Dimorphotheca pluvialis (Asteraceae).These two species have flower heads w ith dark disk florets and yellow or w hite rays.We specu late that G. tulhaghensis is a Batesian mimic o f these spe cies of Asteraceae as it offers no apparent reward to the flies; the flowers lack nectar and the pollen is held distant from the dark centre o f the flow er, so that only the dor sum brushes against them.Captured flies all carried dorsal loads of brow n G. tulhaghensis pollen and ventral loads o f yellow asteraceous pollen.These naked-eye pollen identi fications w ere confirmed by microscopic examination.Available information thus shows two primary pat terns in Geissorhiza.The majority o f species with radi ally symmetric flowers and a short perianth tube have a mixed (or generalist) pollination system using a range o f female bees o f at least four families and worker honey bees, sometimes together with hopliine beetles, and occasionally butterflies, short-proboscid tabanid flies, bee flies and hover flies.Small halietid bees are the most frequent visitors.Visits by Apis mellifera workers may be opportunistic for we have seen no other large-bodied bees o f the family Apidae visiting Geissorhiza flowers.
A second pattern is the specialization for long-proboscid fly pollination in species with narrow, elongate tubes and unilateral stamens.Pollination primarily or exclusively by hopliine beetles is known for just one species, G. cantharophila, but is likely in a few more, e.g.G. tri color described above.Geissorhiza tulbaghensis appears to be a radiate daisy flower mimic.Deceptive pollina tion using short-proboscid Tabanidae is unique not only in the genus but in Iridaceae and we know o f no other examples matching the pollination system we found in G. tulbaghensis.Deceptive pollination using long-pro boscid flies has been inferred for two species o f Hesperantha (Iridaceae) and one o f Pelargonium (Geraniaceae) (Goldblatt et al. 1995(Goldblatt et al. , 2004a) but these species have flowers that mimic those o f similar shape and colour in co-blooming Iridaceae that offer nectar.The record of empidid fly pollination in G. inconspicua is also unusual, and may represent a purely opportunistic event.Too little is known about the role o f Empididae in pollination.
APPENDIX 1.-Keys to subgenera and species o f Geissorhiza.Species numbers follow the classification in Table 1 Key to subgenera
Diagnosis and relationships: according to available records Geissorhiza tricolor was discovered in Septem ber 2006 during a botanical surv ey o f the site o f a new housing development at Riversdale.A collection made by N.A Helme alerted us to the existence o f the plant, which we re-collected in early October.The species is unique in Geissorhiza in its deep yellow flowers with exceptionally broad tepals and a dark, maroon-black central eye.The perianth tube is very short in compari son, 3 -4 mm long.The species recalls G. inconspicua and G. foliosa in vegetativ e morphology but the flowers are larger than in both o f these species and very different in coloration.Geissorhiza foliosa has pink to light purple flowers with a tube ± 5 mm long and tepals 13-17 mm long, and G. inconspicua has blue-violet, pink or white flowers with a perianth tube 4-6 mm long and tepals 8 -11.rarely up to 15 mm long.The flowers o f Geissorhiza tricolor closely resemble those o f orange-flowered Ornithogalum dubium which blooms together with it in the Werner Frehse Nature Reserve and we assume that both species are pollinated
TYPE.-Western Cape.3318 (Cape Town): gravelly, gently north-facing slopes in Darling Nature Reserve, (-A C ), 22 September 1999, Goldblatt & Ndnni 11I62A (NBG, holo.: MO, iso.).Plants 25-50 mm high.Corm bell-shaped, ± 3 mm diam.at widest, basal margin toothed, tunics light brown, concentric, woody.Stem usually I -or 2-branched from near base.Leaves linear.± 1 mm wide, sheaths inflated, plane, ± as long as stem.Main and lateral spikes 1-flow ered; bracts green or flushed purple distally.outer ± 8 mm long, inner ± 6 mm long, not forked at apex.Flow ers actinomorphic.upright, pale yellow, unscented; peri anth tube funnel-shaped, ± 1.5 mm long; tepals narrowly ovate, 6-7 x ± 3 mm.Stamens erect, equal; filaments ± Bothalia 39,2 (2009) 2 mm long; anthers ± 1.5 mm long, pale yellow.Ovary with style erect, dividing opposite upper third o f anthers, style branches recurved, ± 1.5 mm long, bearing promi nent hairs longer than w idth o f branch.Capsules barrel shaped, ± 5 mm long.Seeds ± globose, slightly less than 1 mm diam.Flowering time: September, probably also in late August.Figure 7. Eponvmy: from the Greek, platv, broad, for the unu sually broad style branches.Distribution and ecology: known only from the Dar ling Nature Reserve in the hills above Darling in West ern Cape (Figure 8), Geissorhiza platystigma grows in granite-derived soils on east-and north-trending slopes.The diminutive plants are found locally in open ground or in the shade o f low shrubs in Elytropappus-dominated renosterveld.Diagnosis and relationships: Geissorhiza platystigma is one o f the most inconspicuous species in the genus.Each branch o f the stem is just 30-50 mm high and bears a single flower.Most distinctive are the style branches, which are short and broad and densely covered in promi nent hairs much longer than the width o f the style branch.The flowers are otherwise unremarkable.The corm closely resembles that o f G. ornithogaloides subsp.ornithogaloides in its bell shape with flat base and sharply dentate lower margin.Seemingly immediately allied to this common species o f the coastal and interior o f south ern Cape.G. platystigma differs from it in flower size.Geissorhiza ornithogaloides has a perianth tube 2 -3 (-4 ) mm long, tepals (6-)7-12(-18) mm long, much larger anthers 3.0-4.5 mm long, and the style branches are slender.2-3 mm long, and thread-like as is typical o f the genus.The short, broad and densely hairy style branches o f G. platystigma recall those o f two other species o f the genus from the Darling-Malmesbury area o f Western Cape, G. mathewsii and G. ewystigma.both members of subgenus Geissorhiza.The presence o f unusual style branches in three species o f the genus in this small part o f its range seems to be an unusual coincidence unrelated to its pollination system in view o f the very different floral morphology o f G. platystigma compared to larger, blue and red perianth o f G. ewystigma and G. mathewsii.
T Y P E -Western Cape.3218 (Clanwilliam): Piketberg.lower slopes o f Versfeld Pass, light stony clay in
: spikes o f 1 or 2, large, pale yellow, cup-shaped flowers and the terete, four-grooved leaves, set Geissorhiza sufflava apart in section Angustifolia Goldblatt o f subgenus Weihea.It has the typical, light brown, concentric corm tunics o f the subgenus and falls closest to the widespread, small-flowered G. juncea (Link) D.Dietr.and the southwestern Cape endemic G. furva Banks ex Ker G aul., both of which have similar, terete, four-grooved leaves.O f the two.G. furva has deep yellow flowers w ith a shorter perianth tube 3-5 mm long and tepals 15-22(-28) x 5-8(-9) mm, that spread ± at right angles to the tube when fully open, thus usually smaller and with a different orientation from those o f G. sufflava.Even on warm days, the tepals o f the often larger flowers of G. sufflava remain cupped rather than outspread.The two species appear to differ in ecology and distribution, and G. furva is endemic to the Swartland south of the Piketberg, between Hermon and Paarl, where it occurs in seasonally waterlogged clay flats.A curious feature o f G. furva with an evident biochemical basis is that the tepals turn brownish when dry, often with a dull, metallic grey sheen, whereas those o f G. sufflava retain their pale colour when dry.Additional specimens examined WESTERN CAPE.-3220 (Clanwilliam): 24 km north o f Piket berg, Farm Kliprivier, (-D B ), well-drained stony soil.150 m. 6 Sep tember 2002.Helme 2270 (NBG); Piketberg.lower slopes o f Versfeld Pass, (-D C ), 23 September 1999, Goldblatt 11166.4(MO).
Distribution and ecology: known from just three col lections, one from the upper slopes o f Stalberg in the Kamiesberg o f central Namaqualand.and the other two from Western Cape, on the plateau o f the Gifberg near Vanrhynsdorp and in the Cold Bokkeveld (Figure 8).Plants are localized and evidently uncommon in season ally damp places in the shelter o f granite boulders in the Kamiesberg or among sandstone rocks in the Western Cape mountains.Diagnosis and relationships: imbricate corm tunics, ± plane leaves with margins and central vein only lightly thickened, puberulous stem, and small, star-like flowers with unequal stamens, place G. demissa in the small sec tion Planifolia Goldblatt o f subgenus Geissorhiza (Gold blatt 1985), where it is remarkable for its small size and few-flowered spike.It is evidently closely allied to the widespread G. aspera, a variable species mostly with the flowers dark blue to violet although northern populations trom the Cedarberg and Gitberg have white or bicoloured white and mauve flowers.Geissorhiza aspera is typically larger in all respects and almost invariably branched, w ith leaf blades 2-7 mm w ide, 2-7-flowered spikes, and stems that are puberulous up to the base of the spike, even in the northern, white-flowered populations.The unbranched stems of G. demissa are subglabrous below the spike and the leaves are never more than 1 mm wide.Although the flow ers of the two species are similar in shape, those o f G. aspera are larger, w ith tepals 11-15 x 4-6 mm and similar short filaments, 3-5 mm long, but longer anthers, 3-5 mm vs ± 2 mm long.Geissorhiza aspera is common in the southwestern Cape, trom Swellendam and Bredasdorp northwards to the Gitberg.It is absent from the Bokkeveld Mtns. a short distance to the north, w here the morphologically similar G. inaequalis occurs, a more robust species w ith larger, purple flowers w ith declinate or horizontal stamens.Additional specimens examined WESTERN CAPE.-3118 (Vanrhynsdorp): Gilberg, plateau above pass.(-D B ), 23 August 1984.G oldblatt 7232 (MO).3219 (Wupper tal): Cold Bokkeveld, Wagenboomsriv ier, rocky slopes just northeast o f Waterval, (-C C ), 10 October 2008.Helme 5876 (NBG).

92.
Geissorhiza aren icola L. Bo I us This blue-flowered species o f subgenus Geissorhiza has until now been regarded as endemic to the northern end of the Bokkeveld Mountains and nearby Gifberg range, where, as its name suggests, it occurs in sandy, well-drained soils.Allied to the widespread G. aspera, G. aren icola is recognized by the puberulous stem, two basal leaves with thickened margins and raised and thickened central vein, minutely ciliate on the edges and slightly sticky on the raised surfaces, unequal fila ments and deep blue perianth with tepals mostly 12-15 mm long.We have now collected the species in the Olifants River Mountains west o f Trawal (Goldblatt & Por ter 11888A MO, NBG, PRE).The record establishes its range as a montane species o f the northern portion o f the Northwestern Centre (sensu Goldblatt & Manning 2000) of the Cape floristic region.A collection from Matjiesfontein Farm on the Bokkeveld Escarpment south o f Nieuwoudtville (Goldblatt & Nánni 11154 NBG) consists of uniformly white-flowered plants, and a white-flowered population is also known from Lokenburg.to the south.
55. Geissorhiza exscapa (Thunb.)GoldblattThe recorded range o f Geissorhiza exscapa(Goldblatt 1985), a largely Western Cape coastal species, is from immediately north o f Cape Town on the Farm Blaauw -berg in the south to near Leipoldtville in the north, inland on the Olifants River and Bokkeveld Mountains and in the sandveld inland o f Hondeklipbaai in North ern Cape, the latter a disjunction o f nearly 200 km.New collections from the sandveld west o f Koekenaap on the Farm Kommandokraal (Goldblatt & Porter 13097 MO.NBG) and near Brand se Baai to the north (Goldblatt & Porter 13125 MO.NBG) partly fills the gap in the range, leaving some 120 km betw een the Brand se Baai
Goldblatt When described in 1985, small-flowered species o f section Geissorhiza w as know n only from the imme diate vicinity o f Pakhuis Pass and was thought to be endemic to this limited area, north o f the main Cedar berg range (Goldblatt 1985).Additional collections have now been made some 50 km to the north on the Gifberg summit plateau (26 September 2008, Goldblatt & Porter 13189 MO, NBG) and on sandstone rocks on the Matsikamma Mtns (19 October 1998, Helme 1565 NBG) . D).It also usually has (1)2-5 flowers per spike in contrast to G. monanthos.which has 1(-\) flowers on the main spike and only one each on one or tw o lateral branches.Leav es o f G. monanthos have slightly raised margins and cen tral veins and are always glabrous, w hereas leav es o f G. lewisiae have raised and narrowly winged margins and central veins.Populations o f the species from the vicin ity o f Saldanha have the central vein, margins and sec ondary veins ciliate but populations from Citrusdal and nearby have glabrous leaves.The pollen o f G. lewisiae is pale mauv e or ± w hite but G. monanthos has red-brown or occasionally w hite pollen.
decision to recognize the plants w ith dark, blue-violet flowers with a pale, yel low-green throat as Geissorhiza lewisiae.This species seems to us most closely related to G. aspera w ith w hich it is sometimes sympatric.but it is always distinguished by the larger flower size, unilateral, declinate stamens and style and more intense blue-violet pigmentation than G. aspera which has a ± radially symmetric flower (although an eccentric style), with erect stamens.Both species have one slightly shorter filament.Geissorhiza lewisiae occurs in two disjunct sets o f populations: a northern one around Citrusdal in the Olifants River Val ley, and a western set along the Western Cape coast, from Steenberg Cove on St Helena Bay to Saldanha Bay (Figure 16).Although typically associated with gran ite outcrops, it also occurs on limestone pavement and calcrete in the vicinity o f Saldanha Bay.Geissorhiza monanthos occurs further south, extending from Darling and Mamre (Groenekloof) inland to Malmesbury and south to Klipheuwel and Joostenberg (Figure 16), typi cally occurring on gravelly, granite-derived soils.G eissorhiza m o n an th o s Eckl., Topographisches Verzeichniss der Pflanzensammlung von C.F Ecklon: 21 (1827); R.C.
(flowers we examined had no nectar in the middle o f the afternoon).In contrast, we recorded nectar o f high concentration in one population o f G. karooica (46.5->50 %) and uniform ly > 50 % in a second population o f O', karooica as well as in G. heterostvla and G. ornithogaloides.Populations o f Geissorhiza inflexa w ith small white flowers seem prim arily bee-pollinated; we have cap tured only Apis mellifera on (lowers o f the species at one site, and halietid bees, pierid butterflies and bombylid (lies at another.The large red flowers o f the Tul bagh form o f G. erosa were visited by pollen-collecting female Melitta sp.(M elittidae) and Scrapter heterodoxus (Colletidae) bees and by two species o f hopliine beetles (Table The remaining information about floral ecology of Geissorhiza consists o f observations on pollinator and nectar characteristics accumulated during studies o f the nemestrinid fly Moegistorhynchus longirostris (Nemestrinidae) pollination guild (Manning & Goldblatt 1997) and o f long-proboscid fly pollination systems in south ern Africa (Johnson & Steiner 1997; Goldblatt & Man ning 2000b).Species o f section Engysiphon (subgenus Weihea) with narrow, elongate perianth tubes exceed ing 20 mm. are pollinated exclusively by long-probos cid flies; G. honaspei by Prosoeca nitidula and Philoli che rostrata (Tabanidae); G. exscapa and G. tenella by Moegistorhynchus longirostris and G. confusa by Phi loliche rostrata.We confirm pollination by long-proboscid flies in G. confusa and G. exscapa here w ith a record o f Philoliche gulosa pollinating flowers o f the former in Van der Stel's Pass near Bot River, and M. longiros tris pollinating the latter in the Olifants River Mtns near Graafw ater.We have also obsen.ed G. schinzii o f section Engysiphon being visited by Prosoeca westermannii in the Houw Hoek Mountains, but the flies avoided capture (Table 4).In addition.G. kamiesmontana o f section Ciliata (subgenus Geisshorhiza).which has a perianth tube 18-25 mm long, and G. stenosiphon with a tube 40-50 mm long, are inferred to be pollinated by long-proboscid flies.The violet flower colour in G. kamiesmontana sug gests it belongs to the Prosoeca peringueyi pollination guild (M anning & Goldblatt 1996) and the white flower o f G. stenosiphon suggests pollination by M longirostris or Philoliche rostrata.Nectar o f these long-proboscid fly-pollinated species is o f moderate volume (1.9-5.6 |il) and concentration (19.6-29.0% mean sucrose equiva lents) (references cited above and unpublished for G. schinzii).

TABLE 3 .-Comparison o f taxonomically significant features o f G eis sorhiza erosa and G. inflexa. Filaments are measured from inser tion on perianth tube to base o f anther; for bracts measure the outer bracts in middle o f spike
G. inflexa specimens from the Cape Peninsula and north o f Cape Town have unusually large flowers with tepals ± 17 mm long, anthers ± 6 mm long (e.g.Fellingharn 1617 NBG; Marsh 732 NBG), and are thus apparently interme diate between those of G. erosa and G. inflexa but their pollen grains are o f the G. inflexa type.Geissorhiza erosa (Salisb.)R.C.Foster in Contri butions from the Gray Herbarium o f Harvard Univer sity 135: 52 (1941).Ixia erosa Salisb.: 36 (1796).Type: unknown (possible authentic material at G-Herb.DC.), neotype here designated: South Africa, [Western Cape,] Tulbagh, 9 September 1945, Lewis 5738 (neo., NBG).