Pauridia longituba M.F. Thompson (1972a: 163)

Snijman, Deirdre A., 2014, A taxonomic revision of the genus Pauridia (Hypoxidaceae) in southern Africa, Phytotaxa 182 (1), pp. 1-114 : 44

9. Pauridia longituba M.F. Thompson (1972a: 163) . Fig. 3D

Type (holotype):— SOUTH AFRICA. Western Cape: Farm Witklip 2 miles [3.2 km] Sof Vredenburg [QDS: 3217 DD], in soil pockets on flat granite rock, below 500 ft [152.4 m], 7 June 1965, Thompson 92 ( NBG!; isotypes, NBG!, PRE!)

Plants 1.5–6.5 cm tall. Corm somewhat globose, 6–7 mm diam., covered with reticulate, brown fibrous tunics; fibres attached to basal disc, acute distally; roots slender, arising mainly near corm base. Cataphylls membranous, up to ca. 22 mm long. Leaves 3–9, sheathing at base up to 38 mm, suberect to spreading, linear, 3.5–11.5 × 0.1 cm, canaliculate, margin entire. Inflorescences up to ca. 6 in flower at a time, 1-flowered, shorter than leaves; scape subterranean, hidden amongst leaf bases; bracts 2, clasping ovary base, filamentous, ca. 10 × 0.5 mm, membranous. Flower sessile or minutely pedicellate, tubular-funnelform, white, backs tipped with green or reddish green in outer whorl, slightly acrid-scented; pedicel 0–2 mm long; perigone tube 8–30 mm long, narrowly cylindric for most of length, flaring distally to 2.5–4.0 mm below tepals, tepals 6, spreading, ovate-lanceolate, ca. ⅓–½ as long as tube, 4–10 mm long, outer 2–3 mm wide, minutely mucronate, inner 1.7–2.5 mm wide. Stamens 3, suberect; filaments inserted in throat below inner teplas, 0.4–1.5 mm long, shorter than anthers; anthers oblong, latrorse, 1.5–2.7 mm long, basal lobes up to 0.5 mm long, apex sometimes deeply notched, yellow. Ovary ovoid, ca. 2.5 × 2.0 mm, 3-locular; style slender, ca. as long as perigone tube; stigma branches 3, erect, linear, 2–6 mm long, slightly exceeding stamens, white, margin minutely papillose, bearing a short, downturned lobe at each branch cleft. Capsule ovoid, ca. 3.5 × 2.5 mm, walls moulded over seeds, disintegrating irregularly. Seeds globose, ca. 0.45 mm diam.; testa shiny black to brownish, covered with rounded elevations in close-set, longitudinal rows, outer periclinal walls almost hemispherical, with a flat rim. Flowering period: May–early-June.

Distribution and habitat:— Pauridia longituba , regarded as Endangered ( Raimondo et al. 2009), is localized on granite outcrops along the Western Cape coast between St Helena Bay and Vredenburg ( Fig. 17B ). Several small, fragmented populations are known, usually restricted to shallow pockets of soil on top of isolated rock outcrops. Urban expansion in the area is the major threat to populations.

Diagnostic features:— Pauridia longituba is distinguished by an elongated perigone tube, at least three times longer than the tepals, and the virtual absence of a pedicel which contributes to its pronounced dwarfed habit. Both P. longituba and P. minuta occur on the Witteklip, a massive granite dome on the outskirts of Vredenburg where they superficially resemble one another. Plants of the two species, nevertheless, differ consistently in both pedicel and perigone tube length. Since the pedicel in P. longituba is either entirely lacking or extremely short (up to 2 mm), the flowers are only partially exserted above ground, mainly due to the presence of an elongated perigone tube. Conversely, the flowers in P.minuta are short-tubed and each is held aloft by a well-developed pedicel. Subtle differences in floral fragrances also separate the two species in this area. P. longituba has an unpleasant, acrid odour, whereas the scent in P. minuta is faint but sweet. Despite the distinctly long perigone tube, the various insects seen visiting the flowers of P. longituba are all short-tongued, mainly muscid flies, which apparently feed on the minute amounts of exudate that collects on the downwardly hooked style lobes within the perigone throat.

History:— Pauridia longituba was first discovered by the Cape botanist Mary Thompson in 1964, during her postgraduate studies at the Compton Herbarium, Kirstenbosch Botanic Garden. She described P. longituba eight years later ( Thompson 1972a) after establishing that the plants with long-tubed flowers were indeed distinct from the sympatric P. minuta .

Additional specimens examined:— SOUTH AFRICA. Western Cape: between St Helena Bay and Stompneus Bay (QDS: 3217 DB), 3 June 1970 , Hiemstra 115 ( NBG!) ; 5 km Eof Paternoster , lower Nslopes of Kasteelberg (QDS: 3217DD), 11 June 2009, Helme 6061 (NBG!); Vredenburg, Witteklip (QDS: 3217 DD), 5 June 2004, Rowe & Manning 5 (NBG!); Farm Noodhulp, between Vredenburg and Paternoster (QDS: 3217DD), 2 May 1985, Snijman 844 (NBG!, PRE!); outskirts of Vredenburg, top of Witteklip (QDS: 3217DD), 2 June 1994, Snijman 1440 (NBG!, PRE!), 11 May 2007, Snijman 2108 (NBG!); Farm Witklip (QDS: 3217DD), 16 June 1964, Thompson 21A (NBG!), 7 June 1965, Thompson 89 (NBG!, PRE!); Paternoster (QDS: 3217DD), 8 June 1965, Thompson 95 (NBG!, PRE!); Vredenburg, near Witteklip beacon (QDS: 3217DD), 31 May 1978, Thompson 3815 (NBG!); St Helena Bay, Sterbakenkop, Davids Fonteyn (QDS: 3218CC), 10 June 2009, Helme 6054 (NBG!); 6.6 miles [10.5 km] from St Helena Bay on road to Veldrift (QDS: 3218CC), 14 June 1967, Thompson 290 (PRE!).

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 17. Distribution maps for A, Pauridia minuta from Western and Eastern Cape; B, P. longituba from Western Cape, South Africa.