Mucuna aimun Wiriad., 2016

Wiriadinata, H., Ohashi, H. & Adema, F., 2016, Notes on Malesian Fabaceae (Leguminosae-Papilionoideae) 16. The genus Mucuna, Blumea 61 (2), pp. 90-124 : 103

2. Mucuna aimun Wiriad. , sp. nov. — Fig. 1

Twigs ferruginous tomentose. Petioles 4–8 cm long, rachis 1–3 cm long. Leaflets elliptic or ovate, 6.5–15 by 4–9.5 cm, above ferruginous sericeous to velutinous. Inflorescences pseudoracemes, 15–16 cm long. Calyx campanulate, 11–12 mm long,tube c. 5 mm long.Pods 18 by 3 cm,wings 12–25 mm wide,valves with irregular,transverse lamellae.Seeds 20–25 by 18–27 by 10–12.4 mm. — Type: ANU 2606 (Flenley) (holo L; iso LAE ),W Highlands Prov., Wabag, Ecological site 11, near Yogonda, 1/ 4 mile W of R. Lai.

Liana to 4 m long. Twigs terete, 3–5 mm diam, ferruginous sericeous to velutinous (see Note). Stipules narrowly ovate, c. 21 by 2.5 mm, outside sericeous, inside glabrous. Petioles 4–8 cm long, terete, ferruginous sericeous; rachis mostly as the petiole 1–3 cm long; pulvinus 8–13 mm long. Stipellae acicular, 4 – 6 by 0.2–0.3 mm, hirsute or ± sericeous. Leaflets: terminal elliptic or ovate, 6.5–15 by 4–9.5 cm, index 1.3–1.9, base acute to rounded, apex acuminate, acumen 6 –11 mm long, above sericeous, below sericeous to velutinous, midrib and nerves slightly raised above, nerves 5–7 per side, 8–30 mm apart, anastomosing near the margin; lateral mostly as the terminal 7–13 by 4–6.5 cm; pulvinus 5–8 mm long. Inflorescences axillary, pseudoracemes, 15–16 cm long, peduncle 13.5 cm long, ferruginous sericeous to velutinous. Bracts to the brachyblasts ovate, 20–25 by 5–11 mm, outside sericeous, inside thinly sericeous. Brachyblasts in fruit 2.5– 3 mm long. Bracts to the flowers narrowly ovate, 20–26 by 5–10 mm, outside sericeous, inside thinly sericeous. Pedicels c. 2 cm long (in fruit). Bracteoles narrowly ovate, 20–21 by 2.5– 3 mm, both sides sericeous. Calyx campanulate, 11–12 mm long, tube c. 5 mm long; upper lip triangular, 3 mm long, lateral teeth triangular, 5 mm long, median tooth triangular, 6–7 mm long; outside pubescent and with scattered irritating hairs. Corolla (only immature ones seen). Pods flattened ellipsoid, 18 by 3 cm, sericeous and with irritating hairs, sutures winged, upper wing 15–25 mm wide, lower one 12 mm wide, with irregular transverse lamellae, lamellae interrupted, overlapping in the middle, 8–10 mm high. Seeds flattened ovoid or discoid, 20–25 by 18–27 by 10–12.4 mm; hilum 32–33 mm long, 0.45 of the circumference.

Distribution — Malesia: Papua New Guinea: W Highlands Prov.

Habitat & Ecology — Mountain rain forest, with good drain- age. Altitude 2750–2900 m. Flowering September; fruiting March.

Uses — Seeds eaten.

Specimens seen. PAPUA NEW GUINEA, W Highlands Prov., Wabag , Ecological site 11, near Yogonda, 1/ 4 mile W of R. Lai , alt. 2750 m, ANU 2606 (Flenley), 11 Mar. 1965 ; W Highlands Prov., near Sirunki , alt. 2900 m, ANU 909 (Walker), 19 Sept. 1962 ; E Highlands Prov., Kainantu Subprov., Aiyura , alt. 1500 m, NGF 19030 (Womersley), 8 Sept. 1963 .

Note — Hairs tend to be patent, longest ones 1–2.5 mm long. In vegetative characters M. aimun resembles M. mollissima , M. platyphylla , M. tomentosa and M. verdcourtii . From these species it differs in pod and seed characters.

Figures

Fig. 1 Mucuna aimun Wiriad. a. Leaf; b. piece of twig with a leaf and a part of an infructescence; c. pod from inside; d. seed, top view; e. seed lateral view (all: ANU 2606 (Flenley)). — Drawing Esmée Winkel.