Pauridia pusilla (Snijman) Snijman & Kocyan (2013: 29)

Snijman, Deirdre A., 2014, A taxonomic revision of the genus Pauridia (Hypoxidaceae) in southern Africa, Phytotaxa 182 (1), pp. 1-114 : 55-57

15. Pauridia pusilla (Snijman) Snijman & Kocyan (2013: 29) . Figs. 3C & 25

Bas.:— Spiloxene pusilla Snijman (2006: 135) . Type (holotype):— SOUTH AFRICA. Western Cape, Vanrhynsdorp District, Driekoppen Peak , Gifberg Mountains [QDS: 3118 DD], 2000 ft [610 m], 6 September 1964 , Esterhuysen 30747 ( NBG!, isotypes B!, BOL!, K!, MO!, PRE!, Z!)

Plants 7–19(–30) cm tall. Corm somewhat globose, 4–7 mm diam., loosely covered by dark brown, softly fibrous tunics; fibres reticulate and free from corm base; roots arising from corm base, slender and spreading, or thick and contractile. Cataphylls membranous, up to 10 mm long. Leaves 2–6, sheathing up to 10 mm above base, suberect to slightly arched, narrowly lanceolate, 45–160(–300) × 1.0– 2.5 mm, carinate, pale green, soft and thin-textured, margin entire. Inflorescences 2 or more in flower at a time, 2(3)-flowered, shorter or as long as leaves; scape 20–100 × 0.5–1.5 mm, compressed laterally, sharp-edged, pale green; bracts 2(3), clasping pedicels for at least half their length, lorate, 15–25 × 1–3 mm, foliaceous, shallowly keeled, inconspicuously nerved, pale green, translucent-edged. Flowers pedicellate, stellate, yellow or white, backed with pale green mostly in outer whorl; pedicels suberect in flower and fruit, 20–50(–80) × 0.5 mm, terete, pale green; tepals 4 or 6, rarely 5, reflexed when fully open, narrowly lanceolate, 3–4 mm long, outer 1.5 mmwide and mucronate, inner 1.0– 1.2 mmwide. Stamens as many as tepals, suberect proximally to slightly spreading distally, outer somewhat shorter than inner; filaments yellow with maroon tips, outer 1.4–2.5 mm long, adnate to style for up to ca. 0.5 mm, inner 2.2–3.0 mm long, adnate to style for up to ca. 1 mm, all longer than anthers; anthers oblong, latrorse, 1.0– 1.4 mm long, apical and basal lobes ca. 0.17 mm long and slightly spreading, thecae yellow, connective dark red; pollen yellow. Ovary narrowly ellipsoid, 2.3–3.0 × 0.8–1.2 mm, 2- or 3-locular, beaked distally for 0.5–1.0 mm, beak lengthening up to 1.5 mm when fruiting; style 1.5 mm long, yellow; stigma branches 2 or 3, erect, 0.9–1.5 mm long, shorter than longest stamens, densely papillose, dark red. Capsules narrowly ellipsoid, 2.5–5.0 × 1.0– 1.5 mm, thin-walled, partially topped with withered, persistent ovary beak and perigone, dehiscence irregular from apex downwards; placental ridges remaining contiguous axially; septa disintegrating. Seeds ovoid, ca. 0.5 × 0.4 mm; testa shiny black, of transversally widened cells, forming ca. 12 wide, longitudinal ribs; outer periclinal cell walls with a blunt, raised, central papilla. Flowering period: early September–mid-October.

Distribution and habitat:— Pauridia pusilla is restricted to the northwestern Cape Fold Mountains, where populations are found on the relatively moist summit of the Gifberg and Matzikamma massif near Vanrhynsdorp and on the Pakhuis Mountains east of Clanwilliam, at elevations of 460–760 meters in Western Cape ( Fig. 24B ). Populations are found under south-facing, overhanging, quartzitic sandstone rocks in shallow, sandy soils that are often waterlogged in winter. The plants are often the sole inhabitants of these cool, secluded places, where they form dense mats with the appearance of soft, pale green turf. The flowers remain open throughout the day, unlike those of the sun-loving species of Pauridia which open mid-morning and close mid-afternoon.

This range-restricted species, classified as Rare according to the Red List categories developed specifically for South Africa ( Raimondo et al. 2009), is fortunately protected from agricultural development through its dependence on rocky habitats.

Diagnostic features:— Pauridia pusilla bears a striking resemblance to P. nana in that both are shade-loving plants with delicate, narrow, pale green leaves and small flowers, but several unusual floral characters make the plants of P. pusilla unmistakable. The filaments are fused to the style forming a gynostemium, the anther connectives and stigma branches are reddish and the ovary is topped by a short beak, 0.5–1.0 mm long.

Other species having flowers with a gynostemium are P. maximiliani and the more distantly related and wellknown P. minuta and P. longituba ( Kocyan et al. 2011) . P.maximiliani is similar to P. pusilla in having all the filaments adnate to the style, whereas in P. minuta and P. longituba the inner whorl of fertile stamens is inserted in the perigone throat and only the outer whorl of ‘pseudostigmatic staminodes’, as described by Burtt (2000), is fused to the style, thereby suggesting the independent origin of these structures within Pauridia .

Variation:—Flower colour in Pauridia pusilla varies to some extent throughout its range, although the dark colouring of the anther connectives and stigmatic branches remains constant. The populations on the Matsikamma Mountain and Gifberg invariably have yellow tepals, whereas those in the northern Cederberg have white or cream tepals. Variation in the number of floral parts is also known. Both tetramerous and hexamerous flowers are frequently found within the same population and occasionally on the same plant. Only very rarely have pentamerous flowers been noted. This condition is not unique to the genus, however, and is also known within Hypoxis and Empodium .

Additional specimens examined:—SOUTH AFFRICA. Western Cape: Matsikamma Mountain, Op de berg 314, Dreyers Kloof (QDS: 3118DB), 14 August 1997, Helme 1358 (NBG!); Matsikamma, Farm Sewefontein (QDS: 3118DB), 26 September 1997, Snijman 1623 (NBG!, PRE!), 27 September 2001, Snijman 1860 (NBG!); Gifberg (QDS: 3118DD), 2 September 1948, Compton 20847 (NBG!); Giftberg Mtns (QDS: 3118DD), 15 October 1953, Esterhuysen 22062 (BOL!, NBG!, PRE!); Giftberg Mtns (QDS: 3118DD), 11 September 1911, E.P. Phillips 7569 (SAM!); summit of Gifberg Pass, near De Kom (QDS: 3118DD), 27 September 2001, Snijman 1864 (NBG!); Clanwilliam, ca. 12 km Nof Pakhuis Pass, Verkeerde Vley, Extension 190, NE of Cederhoutkop (QDS: 3218BB), 7 October 2006, Helme 4189 (NBG!); Pakhuis, N Cederberg (QDS: 3219AA), 7 September 1953, Esterhuysen 21722 (BOL!, NBG!), 12 October 1953, Esterhuysen 21910 (BOL!, NBG!, PRE!); N Cederberg, Diagonal Kloof N of Ribbokberg (QDS: 3219AA), 28 October 1987, H.C. Taylor 11869 (NBG!).

Figures

FIGURE 3. Flower diversity in Pauridia. A, P. trifurcillata; B, P. umbraticola; C, P. pusilla; D, P. longituba; E, P. linearis; F, P. gracilipes subsp. speciosa; G, P. curculigoides; H, P. monophylla; I, P.capensis; J, P. canaliculata; K, P. alticola. Photographs by J.C. Paterson-Jones.

FIGURE 24. Distribution maps for A, Pauridia nana from Northern Cape; B, P. pusilla from Western Cape, South Africa.

FIGURE 25. Pauridia pusilla. A, whole plant; B, corm; C, leaf in transverse section; D, flower; E, ovary in transverse section; F, stamens, style and stigma branches; G, capsule; H, seed. Scale bars A = 5 mm; B = 2 mm; C, D, G = 1 mm; E, F = 0.5 mm; H = 0.2 mm. Drawn by Claire Linder Smith from Snijman 1623 (NBG!).