Mucuna angustifolia 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 : 103-105

3. Mucuna angustifolia Adema , sp. nov. — Fig. 2

Liana up to 8 m high. Leaflets narrowly ovate, rarely elliptic, 5.7–11.6 by 1.3–3.9 cm, index 2.6–4.4. Inflorescences axillary, rarely terminal, pseudoracemes, 90–105 cm long, peduncle 75–84 cm long. Pedicels 30–35 mm long. Keel petals 44–46 mm long. Ovules 3–4. — Type: Ridsdale & Reynoso 1420 (holo L), Philippines, Luzon, Zambales, Santa Cruz, Acoje Mine concession area, ultrabasic, 23 May 1986 .

Liana up to 8 m. Twigs terete, striate, 1–3 mm diam, glabrous to very thinly sericeous. Stipules narrowly elliptic, 3–4 by 0.6–0.7 mm, outside with few appressed hairs, inside glabrous, caducous. Petioles 3–6 cm long, ± grooved, glabrous or with few scattered appressed hairs; rachis mostly as the petiole, 0.8– 2 cm long; pulvinus 4–8 mm long. Stipellae acicular, 2.4–4.8 by 0.1–0.3 mm, glabrous or with few appressed hairs. Leaflets: terminal narrowly ovate, rarely elliptic, 5.8–11.6 by 1.3–3.9 cm, index 2.6–4.4, base cuneate or rounded, apex acuminate, acumen 3–15 mm long, above glabrous or with few appressed hairs, below glabrous or with few appressed hairs mainly at midrib, midrib and nerves raised above, nerves 4–7 per side, 3–31 mm apart, anastomosing near the margin; lateral mostly as the terminal, obliquely narrowly ovate, 5.7–11.6 by 1.4– 4 cm; pulvinus 2–6 mm long. Inflorescences axillary, rarely terminal, pseudoracemes, 90–105 cm long, peduncle 75–84 cm long, peduncle mostly glabrous, upwards sericeous, flowering part densely sericeous. Bracts to the brachyblasts ovate, 32–37 by 15–20 mm, outside (thinly) sericeous, inside thinly sericeous, caducous. Brachyblasts 2–9 mm long, sericeous. Bracts to the flowers ovate or elliptic, 19–22 by 6 –11 mm, both sides thinly sericeous, caducous. Pedicels 30–35 mm long, sericeous. Bracteoles elliptic or narrowly obovate, 17.5–22 by 2.5– 6 mm, both sides thinly sericeous, caducous. Calyx 14 mm long, tube 7–10 mm long; upper lip triangular or semicircular, 2–14 by 14–34 mm, lateral teeth triangular, 2.5–5 by 4–6 mm, median tooth triangular, 5–7 by 6–7 mm; outside sericeous and with irritating hairs, inside sericeous. Corolla pale green. Standard: claw 3–4 mm long, glabrous; blade broadly ovate or broadly elliptic, 22–26 by 18–23 mm, bidentate, auricle 1 mm long, outside glabrous or with few appressed hairs in basal part, inside glabrous. Wings: claw 5–6 mm long, outside sericeous along both margins, ciliate along both margins, inside sericeous along both margins; blade elliptic, 35–38 by 8–13 mm, rounded, auricles 3 mm long, lateral pocket 6–8 mm long, outside sericeous between claw and auricle, at auricle and just above, ciliate along lower margin in lower 1/4–1/3, inside glabrous. Keel petals: claw 7–8 mm long, glabrous; blade ± boatshaped, 37–38 by 8–12 mm, acute, auricles 1 mm long, lateral pocket 7–8 mm long, hard part 7 mm long, both sides glabrous, short-ciliate along upper margin. Stamens 44–45 mm long, tube 30–37 mm long, free part of filaments below versatile anthers 8–10 mm long, below basifixed ones 7–8 mm long, glabrous; versatile anthers 1.5 by 0.5 mm, with few hairs at the base, basifixed anthers 2.6 by 0.4 mm, outside with some appressed hairs in basal part. Disc 0.8–0.9 mm high, glabrous. Ovary 6–8 mm long, sericeous, stipe c. 1 mm long, sericeous; ovules 3–4; style 42–43 mm long, sericeous at base, thinning upwards, apical part glabrous. Pods flattened ellipsoid, 13 by 3 cm, upper wing 5 mm wide, lower wing 3 mm wide, lamellae oblique, 2 mm high, valves ± puberulous and with irritating hairs. Seeds discoid, 16 by 15 by 8.1 mm; hilum 41 mm long, c. 3/4 of the circumference.

Distribution — Malesia: Philippines: Luzon, Zambales Prov.

Habitat & Ecology — Secondary forest . Soil: ultrabasic. Altitude up to 200 m. Flowering: May, November; fruiting May .

Specimens seen. PHILIPPINES, Luzon, Zambales Prov., Mansinlok Mine, on road to Bontak, Argent et al. 99290; Luzon, Zambales Prov., Santa Cruz, Acoje Mine concession area, Ridsdale & Reynoso 1420, 1546 .

Note — In many aspects rather similar to M. curranii . The new species differs especially in the narrower leaflets (index: 2.6–4.4, in M. curranii 2.1–2.2); the inflorescence with a longer peduncle, longer pedicels and smaller flowers (44–66 mm long, in M. curranii 69–80 mm long), the indumentum of the corolla parts and the number of ovules (3–4, in M. curranii 4–7). According to the fields notes the colour of the corolla is pale green in the new species and whitish in M. curranii . The new species is recorded from ultrabasic at c. 200 m, while M. curranii is found on limestone at 1300–2200 m.

Figures

Fig. 2 Mucuna angustifolia Adema. a. Twig with lower part of inflorescence; b. upper part of inflorescence; c. standard; d. wing petal; e. keel petal; f. stamens; g. ovary; h. pod; i. seed, top view; j. seed, lateral view (all: Ridsdale & Reynoso 1420). — Drawing Esmée Winkel.