Mucuna kabaenensis Adema, 2016

Wiriadinata, H., Ohashi, H. & Adema, F., 2016, Notes on Malesian Fabaceae (Leguminosae-Papilionoideae) 16. The genus Mucuna, Blumea 61 (2), pp. 90-124 : 111

20. Mucuna kabaenensis Adema , sp. nov. — Fig. 5

Twigs thinly sericeous. Stipellae absent. Leaflets with 2–3 nerves per side. Inflorescences pseudopanicles, 10.5 cm long. Corolla green with purple throat. — Type: McDonald & Ismail 4003 (holo L), Celebes , Kabaena, Gunung Sabampolulu, 1 km S-SE of Tangkeno.Altitude 700–900 m, 3 July 1993 .

Liana. Twigs terete, 3 mm diam, thinly sericeous. Stipules caducous. Petioles 5–6.3 cm long, grooved, striate, thinly sericeous; rachis mostly as the petiole, 2.5–3.7 cm long, pulvinus 5–6 mm long. Stipellae absent. Leaflets: terminal narrowly elliptic or narrowly obovate, 9–9.6 by 4–4.2 cm, index 2.0–2.4, base rounded, apex acuminate, acumen 5–8 mm long, above glabrous or with few appressed hairs, below very thinly sericeous, midrib and nerves more densely so, midrib raised above, nerves flat or slightly raised above, 2–3 per side, 23–36 mm apart, anastomosing near the margin; lateral mostly as the terminal, obliquely, narrowly ovate, 8.7–8.8 by 4.2 cm; pulvinus 5–6 mm long. Inflorescences axillary, pseudopanicles, 10.5 cm long, peduncle 2.5 cm long, thinly sericeous, becoming denser upwards, branches 8–9 cm long. Bracts to the brachyblasts caducous. Brachyblasts 1–2 mm long. Bracts to the flowers caducous. Pedicels c. 26 mm long, sericeous. Bracteoles caducous. Calyx 11 mm long, tube 8–9 mm long; upper lip ± semicircular, 1 by 14 mm, lateral teeth triangular, 1 by 4 mm, median tooth triangular, 2.5 by 5 mm; outside sericeous and with some irritating hairs, inside sericeous. Corolla light green with dark purple throat. Standard: claw 3 mm long, glabrous; blade ± orbicular, 20 by 19 mm, emarginate, auricles 1 mm long, both sides glabrous. Wings: claw 5 mm long, outside sericeous along both margins, ciliate along both margins, inside sericeous along lower margin; blade ± elliptic, 25 by 7 mm, rounded, auricles 2 mm long, lateral pocket 10 mm long, outside sericeous at auricle and just above up to top of lateral pocket, ciliate along lower margin in lower part, inside sericeous along lower margin in lower part. Keel petals: claw 8 mm long, glabrous, ciliate along upper margin in upper part; blade ± elliptic, bent in apical part, 23 by 5 mm, acute, auricles 1.5 mm long, lateral pocket 8 mm long, hard part 5 mm long, glabrous, short-ciliate along upper margin. Stamens 36 mm long, tube 23–29 mm long, free part of filaments below versatile anthers 6 mm long, below basifixed ones 6 mm long; versatile anthers 0.7 by 0.6 mm, bearded, basifixed anthers 2.2 by 0.4 mm, outside with some appressed hairs at base. Disc 0.6 mm high, glabrous. Ovary 7 mm long, sericeous; ovules 5; style 28 mm long, sericeous thinning upwards apical part glabrous.

Distribution — Malesia: Celebes: Kabaena.

Habitat & Ecology — W slopes of Gunung Sabampolulu. Mixed ecotone of grassland and short forest. Soil: serpentine. Altitude 700–900 m. Flowering: July .

Note — Only known from the type. The irritating hairs on the calyx seem to be softer than in other species. Vegetatively similar to M. gigantea , but different in stipellae: absent in the new species, present in M. gigantea and the inflorescences: pseudopanicles in the new species, umbel-like pseudoracemes in M. gigantea . Because of the absence of stipellae similar to M. bennettii , which has much larger, red flowers and M. kawakabuti of Sumba, which differs slightly in the size of the leaflets, in the ratio l/w of the leaflets 2.5–3.0 in M. kawakabuti , 2.0–2.4 in the new species and the number of nerves 6–7 in M. kawakabuti , 2–3 in the new species.

Figures

Fig. 5 Mucuna kabaenensis Adema. a. Habit; b. flower; c. standard; d. wing petal; e. keel petal; f. stamens; g. ovary (all: McDonald & Ismail 400). — Drawing Esmée Winkel.