Jasminanthes maingayi (Hook.f.) Rodda, 2019

Rodda, Michele, 2019, A revision of Jasminanthes (Apocynaceae) with four new species from Borneo, Phytotaxa 405 (3), pp. 127-146 : 137-138

Jasminanthes maingayi (Hook.f.) Rodda comb. nov. ( Figs. 1 , 6)

Marsdenia maingayi (Hook.f.) Forster (1995: 700) ; Yeoh et al. (2013: 244); Stephanotis maingayi Hooker (1883: 39) ; Boerlage (1899: 438); King & Gamble (1908: 550); Ridley (1923: 389).

Type:— Malaysia, Melaka, 23 June 1865 /1866, A.C. Maingay 1731 (Kew Distrib. No. 1112) (lectotype K, [K000821736], designated by Yeoh et al. (2013); isolectotype K [K000821737]) .

Stephanotis elmeri Merr. nom nud. on Elmer 20334 BM [BM000017025], K [K000873055], NY [NY03090919]).

Large woody twining climber, up to 10 m long, latex clear. Leafy stems 2–5 mm in diameter, sparsely pubescent turning glabrescent when mature, older parts lenticellate; internodes (4–)10–15(–20) cm long. Leaves petiolate, petiole channelled above, (1–)2–2.5(–3.5) cm long, 1–2 mm in diameter, sparsely pubescent, lamina elliptic to ovate (5–)8– 10(–22) × (2.5–)3.5–6(–15) cm; base cordate; apex acute, acuminate or apiculate; pubescent along main and secondary veins above, elsewhere glabrous or very sparsely pubescent, underneath pubescent along main and secondary veins, elsewhere glabrous or very sparsely pubescent, basal colleters 5–9 at each lamina base, ovate, 0.2–0.5 mm long, 0.1–0.2 mm wide; venation pinnate, lateral veins 6–9(–11) each side, tertiary venation reticulate. Inflorescences extra-axillary, simple, racemiform, up to 5-flowered; peduncle 2.5–6 cm long, 1.5–2.5 mm in diameter, pubescent to glabrescent. Bracts narrowly lanceolate, 2–8 mm long, outside pubescent, inside glabrous. Pedicel 2–4 cm long, 1–2 mm in diameter, sparsely pubescent. Flower bud just before anthesis fusiform, 4–5.5 cm long, c. 1 cm in diameter, aestivation contorted. Calyx lobes narrowly ovate or lanceolate, apex acute, (10–)15–25 × 4–8 mm, outside sparsely pubescent, inside glabrous, sometimes ciliate; colleters 1–2 occurring between the lobes, oblong, 0.3–0.6 × c. 0.15 mm. Corolla salverform, white fading yellow, tube 16–30 mm long, 3–5 mm wide at throat, adaxially with 5 patches 5–10 mm long of retrorse trichomes in the lowermost part of the tube, upper part of the tube and throat glabrous or pubescent, abaxially sparsely pubescent, lobes lanceolate, 20–30 × 7–11 mm, base asymmetric, apex acuminate, outside sparsely pubescent, inside glabrous. Corona staminal absent; gynostegium conical, 8–9 mm tall, 4–5 mm wide, glabrous. Guide rails 3–4 mm long. Pollinia erect, oblong, 900–1000 mm × 250–350 μm; caudicle c. 500 μm long attached at the base of corpusculum; corpusculum ovate 800–900 × 600–700 μm. Anther appendages erect, covering the style head, ovate, 3–5 × 1.5–2 mm. Style head umbonate, 3–4 mm long, c. 2 mm in diameter. Ovary bi-carpellate, carpels oblong, 2–3 mm long, c. 1 mm wide at the base, glabrous or apically pubescent. Fruit a single follicle c. 25 × 4 cm, glabrous, seed ovate, 1.3–1.5 cm long, 0.7–0.9 cm wide, comose at germinating end, coma 5–8 cm long

Distribution and ecology:— Peninsular Malaysia, Singapore (Yeoh et al. 2013) the distribution of J. maingayi is extended to Borneo based on Dewol Sundaling SAN92361 (A, SAN) and Elmer 20334 (BM, K, NY). It occurs in lowland forests from sea level to 300 m a.s.l.

Conservation status:— Yeoh et al. (2013) considered Marsdenia maingayi as Endangered (EN) based on records from Singapore and Peninsular Malaysia. Using GeoCAT ( Bachman et al. 2011) the revised Extent of Occurrence (EOO) is> 400 km 2 and the Area of Occurrence (AOO) is 24 km 2. As noted in the assessment of J. borneensis , also J. maingayi is likely to occur in many more localities in lowland forests and it is therefore assessed as Least Concern (LC, IUCN 2012).

Notes:— specimen Elmer 20334 was distributed under the name Stephanotis elmeri Merr. The name was never published and is therefore a nom. nud. It is here determined to be J. maingayi . Material from Peninsular Malaysia and Singapore generally has smaller leaves, pubescent peduncles (vs glabrescent on Borneo material). The corolla upper tube and throat is more densely pubescent on Borneo materials. Based on this variability and geographical separation a variety from Borneo might be separated but more collections and observation of fresh material are needed to verify if the characters are stable and taxonomically informative.

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FIGURE 6. Jasminanthes maingayi .. A, Flowering branch; B, a large leaf; C. Calyx and ovary; D, Bud; E, Open corolla; F, A single corolla lobe and section of corolla tube showing the arrangement of the hairs; G, Gynostegium lobe; H, Pollinarium. A, C–H Based on Rodda MR691; B, based on Elmer 20334, drawn by Loh Xiang Yun.

Figures

FIGURE 1. Distribution map of Jasminanthes species in Borneo, based on the examined specimens listed. Generated using SimpleMappr (www.simplemappr.net).