Jasminanthes kinabaluensis Rodda, 2019

Rodda, Michele, 2019, A revision of Jasminanthes (Apocynaceae) with four new species from Borneo, Phytotaxa 405 (3), pp. 127-146 : 135

Jasminanthes kinabaluensis Rodda spec. nov. ( Figs 1 , 5 ).

Similar to J. pilosa because of the thickly pubescent stems and leaves, and asymmetric corolla lobe base; separated because of the smaller calyx lobes, 18–30 × 4–8 mm in J. pilosa vs. 10–15 × 4–5 mm in J. kinabaluensis . and smaller corolla tube (40–50 mm in J. pilosa v. 18–20 mm in J. kinabaluensis ).

Type:—Borneo, Malaysia, Sabah, Dallas, Tinompok ridge, 3500 ft (1066m), 27 October 1931, J. Clemens & M.S. Clemens 26803 (holotype BM [BM000017017], isotypes K, L [L.2716806], NY [NY03090918]).

Stems twining, 3–5 mm in diameter; internodes 10–20 cm long, densely pubescent with straight trichomes. Leaves petiolate; petiole 1.8–2.5 cm long, 1.5–2 mm in diameter, densely pubescent with straight trichomes, lamina ovate, 8– 14 × 4.5–8 cm; base cordate, apex apiculate; adaxial surface sparsely pubescent with more densely pubescent midrib, basal colleters in a cluster of c. 4 at each lamina base, conical; abaxial surface densely pubescent; venation pinnate, lateral veins 6–10 each side. Inflorescences extra-axillary, simple, racemiform, up to 6-flowered; peduncle 1.5–3 cm long, 2–2.5 mm in diameter, pubescent. Bracts at base of pedicels triangular, 6–8 × 1.5–2 mm, inside glabrous, outside pubescent, ciliate. Pedicel 10–15 mm long, c. 1 mm in diameter, densely pubescent with straight trichomes. Flower bud just before anthesis fusiform, c. 5 cm long, c. 1 cm in diameter, corolla lobes contorted. Calyx lobes lanceolate, 10–15 × 4–5 mm, apex acuminate, adaxial and abaxial surfaces pubescent with antrorse trichomes, ciliate; colleters occurring singly or in pairs between the lobes, oblong, c. 0.25 × 0.1 mm. Corolla salverform, tube 1.8–2 cm long, broader at base, narrowest point 3 mm diameter, widest 6 mm diam., throat 3–4 mm wide, adaxially at the base with 5 patches c. 4 mm long of dense retrorse trichomes, c. 1 mm long, the upper part of the tube sparsely pubescent, with spreading trichomes; lobes lanceolate, 25–28 × 8–9 mm, base asymmetrical, adaxially pubescent on the right side of the lobe only, abaxially glabrous, ciliate. Corona staminal absent. Gynostegium conical, 8–9 mm tall, c. 4 mm wide. Guide rails 2.8–3 mm long. Pollinia erect, clavate, 1200–1250 μm × 400–450 mm; caudicle 300–350 μm long; corpusculum ovate, 900–950 × 450–500 μm. Anther appendages erect, covering the style head, c. 4 × 1.5 mm. Style head conical. Ovary bi-carpellate, carpels conical, 1.5–2 mm long, c. 1 mm wide at the base, apex pubescent. Fruit and seed not observed.

Etymology:— named after Mount Kinabalu, where the type specimen was collected.

Distribution and ecology:— only known from the lower part of Mount Kinabalu in Sabah, Malaysia, in montane forests at c. 1000 m altitude, it is the only Bornean species to inhabit such habitat. All other species Bornean species are found in lowland forests below 500 m. However no habitat information is available for J. suaveolens .

Conservation status:— Jasminanthes kinabaluensis is known only from the type collection and its preliminary conservation status is therefore Data Deficient (DD; IUCN 2012).

Notes:— Jasminanthes kinabaluensis can be separated from all other Bornean species because of its extensive pubescence of stems and leaves. A detailed morphological comparison of Jasminanthes species is presented in Tab. 1.

Figures

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

FIGURE 5. Jasminanthes kinabaluensis. A, Flowering branch; B, Calyx and ovary; C, Bud; D, Opening corolla; E, A single corolla lobe and section of corolla tube showing the arrangement of the hairs; F, Gynostegium lobe; G, Pollinarium. Based on Clemens & Clemens 26803, A–F drawn by Chye Lay Choon, G drawn by Loh Xiang Yun.