Dicoelia sumatrana Welzen, 2011

van Welzen, P. C., 2011, Revision of Dicoelia (Phyllanthaceae; Euphorbiaceae s. l.), Blumea 56 (3), pp. 209-213 : 212-213

2. Dicoelia sumatrana Welzen , sp. nov. — Fig. 2 ; Map 1

A Dicoelia beccariana foliis distalibus longiore stipulatis, petalis pistillatis juvenibus aliquantum cucullatis rectis persistentibus in fructu, pistillodio parte basali ovario similis apicaliter stigmatibus 5, columella pyramidali 1–2 mm longa, hilo minuto rotundato differt. — Typus: Achmad 1281 (holo L; iso L, 2 sheets), Sumatra, Simaloer Island [= Pulau Simeulue] .

Shrubs, monoecious, up to 1.5 m high, probably also small trees; flowering branches 3 – 5.5 mm diam. Stipules 4 – 9 by 1.5 –1.6 mm, caducous, but present with several apical leaves. Leaves: petiole 3– 5 cm long; blade 12 –34 by 4.8–14.3 cm, length/width ratio 2.1–2.7, symmetric, papery to somewhat coriaceous, base cuneate, margin flat, apex acuminate, upper surface glabrous except some hairs on the basal part of the midrib, lower surface slightly hairy, venation slightly raised above, nerves 12–15 per side. Inflorescences up to 24 cm long, hairy, round, generally either staminate or pistillate, seldom both sexes together; bracts 1.8– 2 by c. 0.7 mm. Staminate flowers c. 5 mm diam; pedicel 3.5– 6 mm long; sepals 2.1–2.6 by c. 0.8 mm; petals 3 – 4 by 1.7– 2.2 mm, c. 1.1 mm thick; stamens: androphore c. 1 mm high, filaments 0.7–1 mm long; pistillode with basal part c. 8 mm diam; pedicel 8.5–14 mm long; sepals 2.8– 3.7 by 0.9–1.1 mm; petals 4.2 –5 by 1.7–2 mm, apex acute, slightly infolded when young, straight, not infolded when in fruit; gynophore c. 1 mm high; ovary c. 3.2 by 3 mm, style generally absent, conical when present, then 0.8 –1 mm long, stigmas 3 – 3.5 mm long. Fruits 9–11 by c. 13 mm, slightly lobed; sepals and petals persistent, reflexed, straight, not cucullate; columella pyramidal, 1–2 mm long, apically not T-shaped. Seeds 6.5– 9 by 5.8 – 6 by 4.2 –5 mm, hilum small, round.

Distribution — Endemic on Sumatra.

Habitat & Ecology — Soil: granitic sand. Altitude: c. 50 m. Flowering: May, August, September; fruiting: February, May.

Vernacular names — Ketoeh hetoeh or Ketoeh hetoeh pajo (Simalur Island).

Figures

Map 1 Distribution of Dicoelia beccariana Benth. ($) and D. suma- trana Welzen (5).

Fig. 2 Dicoelia sumatrana Welzen. a. Habit; b. staminate flower with sepal and petal removed; c. staminate flower with petals and stamens removed showing androphore with pistillode; d. staminate petal; e. stamen in abaxial view; f. stamen in adaxial view; g. pistillate flower with part of sepals and petals removed; h. young pistillate petal still slightly hooded; i. old pistillate petal under fruit; j. fruit (a–h: Achmad 1281; i, j: Forbes 3246a; all L). — Drawing: Esmée Winkel.