Ceropegia rudatisii Schlechter (1907: 94)

Heiduk, Annemarie, Styles, David G. A. & Meve, Ulrich, 2021, Long-lost Ceropegia rudatisii (Apocynaceae-Asclepiadoideae) - Rediscovered and redescribed after 100 years, Phytotaxa 498 (2), pp. 123-130 : 124

Ceropegia rudatisii Schlechter (1907: 94) . ( Figs. 1 & 2 ).

Type: — SOUTH AFRICA. KwaZulu-Natal Province: Alexandra-County, kurz begraste Weiden bei Fairfield , alt. c. 700 m, December 1905, H. Rudatis 203 (Holotype: B, destroyed) .

Neotype: — SOUTH AFRICA. KwaZulu-Natal: District Alexandra, Station Dumisa, Farm Friedenau , Fairfield , alt. 700 m, 28 February 1908, H. Rudatis 500 ( K000305620 ; designated by Huber (1957: 135); isoneotypes: GH00076275 ; BM000645910 ).

Perennial erect herb. Rootstock producing a cluster of fleshy fusiform roots up to 130 mm long and 4.5–6 mm thick; latex clear. Stems single, rarely two from rootstock, unbranched, annual, green, fleshy, glabrous, 300–500 mm tall, ca. 4 mm in diameter; internodes 20–40 mm long. Leaves ascending to suberect, shortly petiolate; petiole 1.5–2.6 mm long, glabrous; lamina ovate, 39.5–67.5 × 16.5–39.5 mm, flatly spread out, slightly fleshy, fairly stiff, base obtuse, apex acute to acumen, glabrous, blueish-green with thin purple margin, glaucous, with 4–5 lateral nerves. Inflorescences extra-axillary, sessile at youngest node, uniflorous, with single bract 2–4 mm long, lanceolate, acute; pedicel erect, 50– 53 × 1.5–2.0 mm, green, fleshy, glabrous. Calyx lobes narrowly lanceolate, 8.5–18.5 × 0.9–1.1 mm, ascending, acute, pale green, glabrous, about at least 1/2 as long as corolla tube inflation (ostiolum). Flowers with musty-acidic petrollike scent, anthesis c. 3-4 days. Corolla upright or held at a ca. 45° angle from stem, slightly curved from basal inflation (ostiolum), 56.5–85.0 mm in total length; corolla tube 33–48 mm in total length, slightly longitudinally furrowed throughout with furrows being more prominent at mouth; outside glabrous, green merging into purple colouration above ostiolum, and again greenish at throat; inside glabrous smooth throughout; ostiolum whitish with longitudinal purple stripes, stripes thinner at transition to tube; tube dark purple merging into whitish with dark purple coloured reticulation towards throat; ostiolum cylindrical to ovoid, 11.5–21.5 × 5.0–6.0 mm; tube cylindrical, 15.5–24.0 mm long, centrally ca. 2.7 mm in diam.; apical section of tube (mouth) slightly funnel-shaped, 5–7 mm wide. Corolla lobes confluent with the tube, 28.0–43.0 mm in total length, corolla lobe bases short and narrowly strut-like, 2.0– 3.5 mm long, leaving 1.5–2.0 mm wide oval openings between each other, greenish but dark purple at upper sections and with dark-purple recurved margins, corolla lobe tips subulate, 27.5–34.5 × 2.5–3.0 mm, flaccid-pendulous, folded backwards along midrib, exposed upper surface lush green and densely pilose throughout, basally with vibratile trichomes at margins, trichomes clavate, pendulous, 3–4 mm long, purplish. Gynostegium shortly stipitate, dark purple throughout and only basally incl. stipe whitish or whitish and dark purple speckled. Gynostegial corona 3–4 mm in diam., of staminal and interstaminal parts, interstaminal corona lobes joined to form a cup, lobes deeply bifid, lobules ca. 0.8 mm long, small triangular to falcate with the tips spreading, margins pilose with spreading translucent-white trichomes 0.5–1.0 mm long, staminal corona lobes erect, linear, 2.5–3.0 × ca. 0.4 mm, parallel to each other with only the tips slightly recurved, purple, sometimes with whitish tips, glabrous. Pollinarium: pollinia broadly ovoid, ca. 350 × 250 μm, yellow, with rounded insertion crest ca. 150 μm long; caudicles ca. 50 μm long; corpusculum obclavate, but distally oblate and centrally slightly compressed, ca. 205 × 100 μm, reddish brown. Ovaries narrowly conical, ca. 2.2 × 0.5 mm, glabrous. Follicles with two mericarps developed, erect, linear, slightly longitudinally furrowed, 180–210 mm long and 5–7 mm in diam., glabrous. Seeds linear-oblong, 12 × 5–6 mm, flattened, with broad margin, ca. 1.3 mm wide; coma 50–55 mm long, white.

Figures

FIGURE 1. Ceropegia rudatisii from the Dumisa area in KwaZulu-Natal, South Africa.A, Full habit; B, Flower in situ at upper internode of the stem. Note: the flaccid-pendulous corolla lobe tips; C, Plant with well-developed follicles; D, Close up of the openings formed by the corolla lobe bases at the mouth of the tube; E, Close up of the spreading corolla lobes. Photographs:Annemarie Heiduk.

FIGURE 2. Morphological details of Ceropegia rudatisii. A, Longitudinal section through the corolla showing the inner colouration; B, Lateral view of gynostegium and corona (scale bar: 0.5 mm); C, Pollinarium (scale bar: 100 μm); D, Cluster of fleshy fusiform roots; E, Bract (indicated by arrow). Photographs: David Styles (A, D) and Annemarie Heiduk (B, C, E).