Two new species of Spiloxene ( Hypoxidaceae ) from the northwestern Cape , South Africa

Newly described are two new species o f Spiloxene Salisb.: S. nana Snijman from the Bokkeveld Escarpment, Northern Cape Province, is a shade-loving plant with narrow, pale green leaves and small, white or rarely cream-coloured flowers; 5. pusilla Snijman from the Matsikamma, Gifberg and Pakhuis Mountains. Western Cape Province, resembles S. nana in habit but the yellowor white-tepalled flowers which are tetramerous or hexamerous have darkly coloured stamens and style and an ovary with a short, solid, narrow prolongation at the apex. Inhabiting rock overhangs formed by quartzitic sandstone sheets, both species are close allies o f S. scullyi (Baker) Garside from Namaqualand. With about 30 species, Spiloxene Salisb. is the largest genus of the family Hypoxidaceae in the Greater Cape Floristic Region, which corresponds geographically with the winter and all-year rainfall region of southern Africa. The genus, as presently circumscribed, was first sepa­ rated from Hypoxis L. by Williams (1901) who reinstated the name Ianthe Salisb. that was originally applied to just three species (Salisbury 1866). Despite its early history, the genus has nevertheless remained one of the most poorly studied groups of Cape geophytes. The last com­ prehensive revision of the genus was that of Nel (1914) who, having taken into account that the letters I and J are interchangeable in the transliteration of the Greek letter ‘iota , re-introduced the spelling Janthe, which was first used by Pax (1887) for a section of Hypoxis. Fourcade (1932) then changed the name to Spiloxene following the discovery that Ianthe Salisb. (Salisbury 1866) is a later homonym of Janthe Griseb. (Grisebach 1844), which has become a synonym of Celsia L. in the family Scrophulariaceae. In two recent regional treatments, the accounts of Spiloxene included an undescribed species, which was referred to as 'sp. 1 ’ (Snijman 2000a; Manning et al. 2002). In the short period following the preparation of these publications, however, new material has been col­ lected that clarifies what was proposed as the new spe­ cies. It has become apparent that what was previously regarded as one species actually comprises two species of shade-loving plants that are separated from one another geographically. The new species are described and illustrated here as Spiloxene nana from the Bokkeveld Escarpment near Nieuwoudtville, Northern Cape, and S. pusilla from the Matsikamma-Gifberg massif near \anrhynsdorp and the Pakhuis Mountains in the northern Cederberg, Western Cape. Spiloxene nana Snijman, sp. nov., quoad habitum et floribus parvis ad S. pusillae Snijman, sed ab ea differt hlamentis e basi libris, antheras et stigmatibus luteolis (haud rubiginosis). Ab S. scullyi (Baker) Garside foliis 1.5-5.0 mm (nec 3-14) mm latis, floribus 2 (nec 2-5), * Compton Herbarium, South African National Biodiversity Institute, Private Bag X7, 7735 Claremont, Cape Town. MS. received: 2006-04-18. albis raro cremeis (non luteis), ovario triloculare (non uniloculare) et placentatio axilis (non parietali) facile distinguitur. Figura 1. TYPE.—Northern Cape, 3119 (Calvinia): Oorlogskloof Nature Reserve, 773 m, (-AC), 11-10-200 W.A.J. Pretorius 589 (NBG, holo.; K, MO, PRE). Deciduous, entirely glabrous, softly herbaceous, cormous plant, 95-350 mm high. Corms growing horizontal­ ly or geotropically; new corms somewhat globose, 4-10 mm diam., loosely covered by brown tunics; old corms persisting for a few seasons as withered, flattened discs; innermost tunics papery, outermost softly fibrous; fibres fine, reticulate and free from corm base; roots dimorphic, arising from near base of new corm, slender and spread­ ing, contractile and geotropic. Shoot arising laterally, sur­ rounded at base by a membranous cataphyll up to 45 mm long. Foliage leaves synanthous, 2-6, 3-ranked in a basal tuft, sheathing from ± 10-30 mm at base; blades suberect to slightly arched, narrowly lanceolate, V-shaped in t/s, 35-350 x 1.5-5.0 mm, the innermost narrowest, pale green, soft and thin-textured, keeled abaxially almost to apex; margins entire. Inflorescences 2 or more, erect, a 2-flowered umbel-like raceme; scape 30-150 x 0.5-2.0 mm, laterally compressed, pale green with membranous lateral edges; bracts 2, opposite, partially sheathing pedicels proximally, lanceolate, 10-40 x 3^4 mm, foliaceous, shallowly keeled, inconspicuously nerved, pale green, with translucent margins. Flowers stellate, usu­ ally opening sequentially, unscented; pedicels suberect at anthesis thereafter spreading horizontally, triangular in t/s, 35-80 x 1 mm, slender, pale green; tepals 6 , reflexed when fully open, narrowly lanceolate, 2.5—7.0(—12.0) mm long, white or rarely cream-coloured, occasionally flushed pink, backed with pale green in outer whorl, outer tepals 1.5-2.5 mm wide and mucronate, inner tepals 1-2 mm wide and minutely mucronate. Stamens 6 , slightly spreading, unequal, outer whorl slightly shorter than inner; filaments inserted at base of tepals and joined to sinus between anther lobes, filiform, 0 .51.5 mm long, yellow; anthers latrorse. oblong. 1.5-2.0 mm long before opening, yellow, apical and basal lobes slightly spread­ ing and ± 0.05 mm long; pollen yellow. Ovary inferior, narrowly tubular to ellipsoidal, 2.5-8.0(-l 1.0 ) x 0 .72.0 mm, 3-locular with axile placentation, narrowed distally 134 Bothalia 36,2 (2006) FIGURE 1.—Spiloxene nana. A. B. Pretorius 5H9. C F, Rnurke 22IX A. whole plant, including t/s leaf; B, corm; C. flower; I), stamens, style column and stigmatic branches; E, capsule; F. seed. Scale bars: A. 5 mm; B, 2 mm; C, 2.5 mm, D, 1 mm; E. 3 mm; F. 0.2 mm. Artist: John Manning. Bothalia 36,2 (2006) 135 into an inconspicuous, solid, ± 0.5 mm prolongation that sometimes extends up to 1 mm after anthesis; ovules 15-20 per locule; style column cylindrical, 0.3-0.5 mm long, white; stigmatic branches 3, erect but even­ tually spreading, 1.2-3.0 mm long, tapering upwards from broad base, with edges of abaxial surface slightly folded together, densely papillate on margins and edges of adaxial surface, white. Capsule narrowly ellipsoidal. 2.5-11.0 x 1.0-2.0 mm, thin-walled, shedding withered ovary beak and perigone; dehiscence loculicidal, irregu­ larly longitudinal; placental ridges remaining contiguous axially; septa disintegrating. Seeds depressed-ellipsoi­ dal, 0.53 x 0.43 mm; funicle stout, attached in chalazal hemisphere; micropyle prominent; testa brittle, lustrous black with wicker basket-like ornamentation, consisting of ± 15 longitudinal rows of closely set, transversally widened cells; outer periclinal walls each with a central, conical, raised papilla. Figure 1. Phenology: Spiloxene nana is spring flowering, mostly from the middle of September to late October. The leaves are green during the winter and spring but die back dur­ ing the onset of the dry conditions which extend through summer and autumn. Distribution and habitat: the species is known only from the Bokkeveld Escarpment near Nieuwoudtville, Northern Cape (Figure 2), where it was first collected by Mrs L. Bolus in 1930. Surrounded by sheer quartzitic sandstone cliffs belonging to the Nardouw Formation, the Escarpment is deeply dissected by the Oorlogskloof River which Hows through a 100 m deep gorge. Spiloxene nana is found on the Escarpment’s southwest-facing slopes which are relatively moist and cool, unlike the hotter and drier slopes that face northeast. Several popu­ lations, sometimes comprising as many as 500 plants in each, have been recorded in and around the Oorlogskloof Nature Reserve. Individuals are usually massed together in shallow soil under damp, shaded rock ledges at 730-770 m. Although locally dominant in small patches, other tiny, shade-loving plants may co-occur, especially the softly herbaceous, annual species, Crassula strigosa. FIGURE 2. Known distribution o f Spiloxene nana. • in the Northern Cape Province; and S pusilla. A . in the Western Cape Province. Diagnostic features: as the epithet suggests, Spiloxene nana is characterized by slender leaves, 1.5-5.0 mm wide, and relatively small flowers ranging from 5—12(— 20) mm across. In addition, the flowers are inconspicu­ ously coloured—white or rarely cream-coloured with a pink flush, but always with pale green on the backs of the outer tepals—and the tepals usually reflex downwards when fully mature. Although the leaves are fairly long (up to ± 350 mm) they are characteristically soft and pale green with a delicate appearance. Its affinities seem to lie primarily with Spiloxene pusilla, which closely resembles S. nana in habit. Furthermore, the somewhat membranous leaves and the thin-textured. pale green foliaceous bracts sug­ gest that S. nana and S. pusilla are allied to S. scullyi (Baker) Garside. a species found in the granite hills of Namaqualand and which belongs to Nel’s Aquaticae group (Nel 1914). Although Nel described the corms of the five species in this group as lacking persistent fibres and the disc-like remnants of old corms. those of S. scul­ lyi may sometimes be softly fibrous towards the apex and may retain a few old discoid corms laterally Both these features are shown, for example, in Pearson 6585 (BOL) and Scully s.n. (Herbarium Normale Austro-Africanum 1381 in SAM). S. scullyi differs from S. nana and S. pusilla. however, in generally being more robust. It has broader leaves. 3—9(—14) mm wide, and considerably larger flowers. 14—28(—38) mm across, which are plain yellow above. Most importantly, the ovary in S. scullyi is unilocular with parietal placentation. Like most other Spiloxene species, the ovary in S. nana or S. pusilla is trilocular with axile placentation. The similarities and differences between Spiloxene nana and S. pusilla are fully discussed below under S. pusilla. Other specimens examined NORTHERN CAPE.— 3119 (Calvinia): stream feeding waterfall ± 10 miles out o f Nieuwoudtville. (-A C ). L.Bolus (BOLI9597); Oorlogskloof trail near Nieuwoudtville.

With about 30 species, Spiloxene Salisb. is the largest genus of the family Hypoxidaceae in the Greater Cape Floristic Region, which corresponds geographically with the winter and all-year rainfall region of southern Africa.The genus, as presently circumscribed, was first sepa rated from Hypoxis L. by Williams (1901) who reinstated the name Ianthe Salisb.that was originally applied to just three species (Salisbury 1866).Despite its early history, the genus has nevertheless remained one of the most poorly studied groups of Cape geophytes.The last com prehensive revision of the genus was that of Nel (1914) who, having taken into account that the letters I and J are interchangeable in the transliteration of the Greek letter 'iota , re-introduced the spelling Janthe, which was first used by Pax (1887) for a section of Hypoxis.Fourcade (1932) then changed the name to Spiloxene following the discovery that Ianthe Salisb.(Salisbury 1866) is a later homonym of Janthe Griseb.(Grisebach 1844), which has become a synonym of Celsia L. in the family Scrophulariaceae.

Spiloxene nana
Phenology: Spiloxene nana is spring flowering, mostly from the middle of September to late October.The leaves are green during the winter and spring but die back dur ing the onset of the dry conditions which extend through summer and autumn.
Distribution and habitat: the species is known only from the Bokkeveld Escarpment near Nieuwoudtville, Northern Cape (Figure 2), where it was first collected by Mrs L. Bolus in 1930.Surrounded by sheer quartzitic sandstone cliffs belonging to the Nardouw Formation, the Escarpment is deeply dissected by the Oorlogskloof River which Hows through a 100 m deep gorge.Spiloxene nana is found on the Escarpment's southwest-facing slopes which are relatively moist and cool, unlike the hotter and drier slopes that face northeast.Several popu lations, sometimes comprising as many as 500 plants in each, have been recorded in and around the Oorlogskloof Nature Reserve.Individuals are usually massed together in shallow soil under damp, shaded rock ledges at 730-770 m.Although locally dominant in small patches, other tiny, shade-loving plants may co-occur, especially the softly herbaceous, annual species, Crassula strigosa.Diagnostic features: as the epithet suggests, Spiloxene nana is characterized by slender leaves, 1.5-5.0mm wide, and relatively small flowers ranging from 5-12(-20) mm across.In addition, the flowers are inconspicu ously coloured-white or rarely cream-coloured with a pink flush, but always with pale green on the backs of the outer tepals-and the tepals usually reflex downwards when fully mature.Although the leaves are fairly long (up to ± 350 mm) they are characteristically soft and pale green with a delicate appearance.
Its affinities seem to lie primarily with Spiloxene pusilla, which closely resembles S. nana in habit.Furthermore, the somewhat membranous leaves and the thin-textured.pale green foliaceous bracts sug gest that S. nana and S. pusilla are allied to S. scullyi (Baker) Garside.a species found in the granite hills of Namaqualand and which belongs to Nel's Aquaticae group (Nel 1914).Although Nel described the corms of the five species in this group as lacking persistent fibres and the disc-like remnants of old corms.those of S. scul lyi may sometimes be softly fibrous towards the apex and may retain a few old discoid corms laterally Both these features are shown, for example, in Pearson 6585 (BOL) and Scully s.n.(Herbarium Normale Austro-Africanum 1381 in SAM).S. scullyi differs from S. nana and S. pusilla.however, in generally being more robust.It has broader leaves.3-9(-14) mm wide, and considerably larger flowers.14-28(-38) mm across, which are plain yellow above.Most importantly, the ovary in S. scullyi is unilocular with parietal placentation.Like most other Spiloxene species, the ovary in S. nana or S. pusilla is trilocular with axile placentation.

Other specimens examined
Phenology-, flowering extends throughout spring from early September to mid-October.The leaves remain green tor slightly longer until the onset of the summer dry period, when they are shed.New leaves emerge each year with the onset of winter rain which often starts to tall in autumn.Most species of Spiloxene depend on sunshine to open their flowers (lasting from ± 11:00 to ± 16:00), but those of S. pusilla are able to open in the shade and to remain open throughout the day.
Distribution and habitat: Spiloxene pusilla is restrict ed to the northwestern Cape Fold Mountains (Figure 2), where populations are found on the relatively moist, cool summit of the Gifberg and Matzikamma massif, near Vanrhynsdorp.and on the Pakhuis Mountains east of Clanwilliam.at 460-760 m.These mountains have large areas of exposed, flat, quartzitic sandstone sheets that are often waterlogged in winter and are extremely dry in summer.The plants shelter under south-facing, overhanging rocks in shallow, sandy soil, where they escape the severe conditions of the exposed rock sheets.S. pusilla is often the sole inhabitant of these cool, shady, shelf-like habitats, where it forms dense mats having the appearance of soft, pale green turf.
Diagnostic features: one of the most unusual features of this species, and perhaps the most important reason why it has remained unnamed for so long, despite sev eral collections having been made since its discovery by E.P. Phillips in 1911. is the fusion of the inner filaments to the style.Handwritten notes by the late Ms M.F.Thompson (Mrs Rand), author of several papers on Cape Hypoxidaceae (Thompson 1969(Thompson , 1976a(Thompson . b. 1978(Thompson , 1979)), suggest that she regarded the fusion of the filaments to the style to be sufficiently significant to delay formally describing the species until its relationships were more clearly understood.Fortunately, the availability of many more collections of the newly described and apparently closely related S. nana has made this description pos sible.
Morphologically Spiloxene pusilla bears a striking resemblance to S. nana.Both are shade-loving plants with delicate, narrow, pale green, extremely soft-textured leaves and small flowers, often only 10 mm in diameter.In addition, both species inhabit rock overhangs where the plants form dense, turf-like patches.
The particular features that separate Spiloxene pusilla from 5. nana are those of the flower.The inner filaments are shortly fused to the style (versus free from the style); the anther connectives and stigmatic branches are dark red (as opposed to yellow); and the ovary is constricted into a short (0 .5-1.0 mm) but distinct solid, neck-like prolongation at anthesis (compared with an indistinct prolongation of up to ± 0.5 mm that sometimes lengthens slightly after anthesis).
Elsewhere in the family a solid prolongation of the ovary, most often referred to as the ovary beak, is found in Empodium Salisb.. Curculigo Gaertn., Molineria Colla.Rhodohypoxis Nel and Saniella Hilliard & B.L.Burtt (Hilliard & Burtt 1978), and although infrequent in Spiloxene, it is well developed in S. alba (Garside 1950).Moreover, the darkly coloured stamens and style, in otherwise yellow or white flowers, are only known in Spiloxene.particularly in the southwestern Cape species.S. canaliculata Garside.S. capensis (L.) Garside and 5. serrata (Thunb.)Garside, which belong to a guild of beetle pollinated plants (Steiner 1998).Undoubtedly the flowers of S. pusilla are too small to support monkey beetles, but their dark filaments and stigmas may attract specific, albeit tiny, pollinators an aspect which is yet to be studied.Records show that this dark coloration is constant throughout the distribution range but that popu lations on the Matsikamma Mountain and Gifberg con sistently have yellow tepals.whereas those in the north ern Cederberg have white or cream-coloured tepals.
Although Figure 3 shows a plant with tetramerous flowers, this is not constant in the populations, and hexamerous flowers also frequently occur, occasionally even on the same plant.Only very rarely has a pentamerous flower been noted.This variation in the number of floral parts is not unique and is also known in species of Hypoxis and Empodium.
Lastly, the only other member of Hypoxidaceae that has parts of the androecium fused to the style is Pauridia Harv., a small Western Cape genus of two species.Pauridia, however, is characterized by tepals that are joined below to form a cup-shaped or tubular perigone; an inner whorl of fertile stamens which is inserted in the perigone throat; and an outer whorl of staminodes that is fused to the style.Moreover, the stigmatic branches are slender and distinctly shorter than the sty le column.This is in contrast to Spiloxene pusilla, in which all six stamens are fertile, the flowers are stellate, and the stig matic branches are distinctly broader and longer than the style column.These features, together with the cormous habit, are common to all the currently known species of Spiloxene, which suggests that this northwestern Cape species is best placed within Spiloxene.
Despite clear evidence from leaf anatomy and rbcL sequence data that Spiloxene and Pauridia are closely related (Thompson 1976a;Hilliard & Burtt 1978;Nordal 1998;Rudall et al. 1998;Burtt 2000;Judd 2000), both genera have been consistently retained in local floras (Garside 1950;Snijman 2000a, b).Should future studies reveal, however, that Spiloxene and Pauridia comprise one monophyletic genus, it nevertheless seems likely, given the different relative positions of the structures involved, that the fusion of filaments to style in S. pusilla is not homologous with the fusion of staminodes to style in P. minuta (L.f.) Durand & Schinz and P. longituba M.F.Thomps.

FIGURE 2 .
FIGURE 2. Known distribution o f Spiloxene nana.• in the Northern Cape Province; and S pusilla.A . in the Western Cape Province.