Kamiesbergia , a new monotypic genus of the Amaryllideae-Strumariinae ( Amaryllidaceae ) from the north-western Cape

Kamiesbergia Snijman is a new monotypic genus from raised granite outcrops in the north-western Cape. A member of the subtribe Strumariinae of the Amaryllideae, it is most closely related to Hessea Herb, and Namaquanula D. & U. Miiller-Doblies. The dissimilar inner and outer stamens, the uniquely club-shaped inner filaments and the novel insertion of the filament in the proximal quarter of the anther connective are the main apomorphies of the genus. The number of rare and monotypic genera of Amaryllidaceae in this region is comparable to that of Andean South America.


INTRODUCTION
The tribe Amaryllideae sensu Traub (1965Traub ( , 1970) ) and Dahlgren et al. (1985) is uniquely defined by bisulculate pollen grains (Dahlgren & Clifford 1982; Dahlgren et al. 1985;Erdtman 1966;Schulze 1984) Since this new species lacks all the derived character states of the genera already described within the Stru mariinae.and since it possesses a set of unique characters that justifies its separation at the generic level, the taxon is described here as the new monotypic genus Kamies bergia.

MATERIALS AND METHODS
This study was based on herbarium material from BM. BOL, K. NBG, PRE.SAM and WIND.Ecological information was derived from field studies during the flowering, fruiting and leafing stages of the species.Fresh non-acetolyzed pollen grains for scanning electron micro scopy (SEM) were dehydrated in ethanol, critical point dried and coated with Au/Pd.Photographs were taken with a Cambridge 200 SEM at 10 kv.Chromosome data were gathered from actively growing root tips, pretreated with saturated alphabromonapthalene at 4°C for 24 hours, then fixed in 1:3 acetic acid/ethanol.The root tips were hydro lysed in normal hydrochloric acid at 60°C for six minutes, stained with Feulgen for 30 minutes, counterstained with 2 % aceto-orcein and then squashed.Photographs were taken with a Zeiss Axioskop.Bulbous perennial herb, up to 210 mm tall.Bulb soli tary, deep-seated, subglobose, 12-30 mm across, with thin light-brown parchment-like outer tunics, fleshy and whitish within, extended into a long slender neck up to 110 mm.Leaves absent at anthesis or rarely persisting to anthesis, 2 ( -3 ) , spreading, narrowly lorate, 6 0 -3 0 0 x 1 -3 mm, glabrous, with the adaxial surface shallowly canaliculate, subtended by a subterranean non-amplexicaul prophyll.Inflorescence slightly spreading, 4 0 -8 0 mm across; scape stiffly erect, 50-140 mm long, 1 -2 mm diam., greyish pink to leaden-grey, breaking off at the base in fruit; spathe valves linear-lanceolate, 15-30 X 1 -2 mm; bracteoles filiform, up to 5 mm long.Flowers 5 -9 , ascending, hypocrateriform, pale lemon-yellow, usually with a greenish to reddish brown tube, flushed dorsally with reddish brown on the outer tepals, ageing to light brown, scentless; pedicels straight to upwardly curved, 3 5 -6 0 mm long, green.Tepals recurving from a narrow 8 -1 2 mm long tube, narrowly lanceolate, 6 -8 x 2 -3 mm, slight ly channelled.Stamens in 2 unequal whorls, epitepalous, filaments basally connate into a greenish yellow tube extending to 0,5-1,0 mm above the perigone throat, free above, reduced to a 0,25 mm long filiform free tip in the outer whorl, prominent and spreading in the inner whorl; the inner filaments free for 3 -4 mm, clavate in the distal half with a subulate tip; anthers dorsifixed near the base, ± 2 ,5 mm long and maroon before opening; the outer anthers occluding the perigone throat after dehiscence; pollen cream-coloured.Ovary subglobose, 2 -3 mm across, with up to 4 -6 ovules per locule.Style erect, slender throughout, up to 5-11 mm long, remaining included in the perigone tube; stigma shortly trifid, shortly penicillate on the inner surface.Fruit a subglobose, papery, loculicidal capsule, 7,5 mm across.Seeds fleshy, ovoid, up to 2,5 mm across, reddish brown when ripe.Chromo some num ber: 2n = 22. Figure 1.The presence of a perigone tube is considered to be plesiomorphic in the subtribe (Muller-Doblies 1985).In most species of Hessea the perigone tube is reduced and the tubular component is formed by the extension of the perigone/stamen confluence into a winged tube, a feature which is considered to be derived (Miiller-Doblies 1985).Only H. longituba D. & U. Miiller-Doblies has a pronounced smooth perigone tube comparable to that of K. stenosiphon, which may suggest a close relationship between the two taxa.A critical evaluation of the key androecial states in Hessea and K. stenosiphon however, does not support such a relationship.

Kamiesbergia stenosiphon
The main synapomorphy for Hessea is the insertion of the filament into a connective sheath, in which the length of the dorsal wall almost equals that of the ventral wall: a condition known as centrifixed anther insertion (Miiller-Doblies 1985).This character state is interpreted as the extreme in a morphological series ranging from dorsifixed to subcentrifixed and centrifixed anther insertion, with each state being found in the Strumariinae.In contrast, a transformation series between the centrifixed anther insertion of Hessea and the almost basifixed anther insertion (without a connective sheath) of K. stenosiphon could not be established from current data.Thus a sister group relationship between the two genera cannot be inferred.
The bisulculate pollen grains are globose, isopolar and have scattered large spinulae on the surface (Figure 2).The karyotype of K. stenosiphon (Figure 3) comprises a pair of large submetacentric chromosomes; six pairs of medium-sized metacentric to submetacentric chromo somes, of which one pair is a satellite chromosome; and four pairs of shorter metacentric to submetacentric chromosomes.The chromosome phenotypes are similar to those of most Amaryllideae with x = 11 (Goldblatt 1972(Goldblatt , 1976;;Jones & Smith 1967).A karyotype of x = 11 is con sidered basic in the family (Inariyama 1937;Meerow 1984;Sato 1938).
Distribution and habitat records indicate that K. stenosi phon is rare.Known populations are restricted to the north western Cape and are widely disjunct in the eastern Kamiesberg and near Pofadder (Figure 4).In the Kamiesberg, the deep-seated bulbs grow in loamy soils which accumulate in seasonally moist crevices and water-worn gullies on massive exposed granite domes, at The discovery of Kamiesbergia, a further monotypic genus in the Amaryllideae, brings into focus the parallels which exist in this respect between the Amaryllideae of South Africa and the Andean Amaryllidaceae of South Ameri ca.Goldblatt's suggestion (Meerow 1985) that similar evolutionary patterns exist between the Amaryllidaceae of these two geographical centres is yet to be examined.
. As presently circum scribed (Muller-Doblies 1985), the subtribe Strumariinae of the Amaryllideae currently includes four small and three monotypic genera (Namaquanula D. & U. Miiller-Doblies.Hessea Herb., Carpolyza Salisb., Strumaria Jacq., Bokkeveldia D. & U. Miiller-Doblies, Gemmaria Salisb.and Tedingea D. & U. Miiller-Doblies).Character states common to these genera are the actinomorphic flowers and the reduced size of the plants.Exclusively southern African, the subtribe comprises approximately 35 species, which are concentrated in the semi-arid winter rainfall regions of the Cape Province and southern Namibia.Phylogenetic studies in the Strumariinae (Snijman unpubl.),revealed an undescribed A/fssf'a-like species from the north-western Cape.A character analysis confirmed the presence of bisulculate pollen grains but indicated that the taxon did not fit into any known genus of the Strumariinae.The new species lacks the synapomorphy of x = 10 and the adnation of the filaments to the style, which characterises Carpolyza, Strumaria and its close allies Bokkeveldia, Gemmaria and Tedingea; it lacks the centrifixed anther insertion which is synapomorphic for H essea; and is without the adaxially-hooked filaments which characterise Namaquanula.Character states unique to the new taxon are the dissimilar inner and outer stamens, the club-shaped distal half of the inner filaments, and the filament attachment near to the base of the anther connective.

Flowering
time extends from the end of April to May.In most bulbs the foliage leaves commence growth shortly after flowering and subsequently die back at the onset of the summer drought.Occasionally some bulbs which occupy wetter, cooler sites have been noted with green leaves throughout the summer.Diagnostic features of K. stenosiphon are the form of the stamens and anther insertion.The inner filaments are at least twelve times as long as the outer filaments and are uniquely club-shaped in the distal half with a subulate tip.The stamens of the short outer whorl occlude the perigone throat after dehiscence.Unlike the medifixed anthers common to all other Strumariinae, the filaments of Kamiesbergia are attached in the proximal quarter of the connective (Figure 1.6c & 1.7c).