Actephila discoidea Heijkoop & Welzen, 2017

Heijkoop, M. & Welzen, P. C. van, 2017, A revision of the genus Actephila (Phyllanthaceae) in the Malesian region, Blumea 62 (1), pp. 7-25 : 11-13

2. Actephila discoidea Heijkoop & Welzen , sp. nov. — Fig. 2 ; Map 2

Resembling A. lindleyi by the short, straight fruiting pedicels and relatively short, often completely glabrous petioles. Differing from A. lindleyi in leaf shape being often ovate, with the base often acute and the apex usually longer, and the presence of a thick, fleshy nectar disc (vs leaf blade elliptic (to obovate), base usually attenuate, apex usually acute, disc thin in A. lindleyi ). — Type: Takeuchi & Towati 14639 (holo L; iso probably in A, LAE ), Papua New Guinea, Morobe Province, Kamiali Wildlife Management Area, ridge inland of Cape Roon, slopes above side baret of the Ariwiri River, near S07°19.6' E147°07.5'.

Shrubs to tree(let)s, 1–5 m high, monocaulous to sparsely branched; flowering branches 2–4 mm diam, with brown lenti- cels, sometimes somewhat puberulous at branch tips. Indumentum : most parts subglabrous. Stipules deltoid to broadly ovate, 1.5–3 by 1.2–2 mm, glabrous. Leaves: petioles 0.5–3.8 cm long, pulvinate at both ends, often glabrous, sometimes slightly sericeous, striate when dry, sometimes with transverse grooves, somewhat corky when older; blade ovate to elliptic, 11–30.5 by 2.6–9.3 cm, 2.6–4.3(–5.1) times as long as wide, fleshy when fresh, papyraceous when dry, base obtuse to acute, margin flat, apex gradually tapering, widely caudate to cuspidate, tip acute, adaxially dull to glossy, light to dark green, abaxially paler green than adaxially to yellow-green or slightly glaucous, glabrous; nerves 9–14 per side. Flowers solitary, on brachyblasts when older. Staminate flowers not seen. Pistillate flowers not seen, observations from fruit: sepals broadly ovate, widest at base, c. 3 by 2–2.5 mm, apex acute to obtuse, often glabrous on both sides; disc a thick fleshy, wide ring, substantially covering the base of sepals in fruit. Fruits dull, immature glaucous green to green, 1.5–1.7 cm diam, erect, glabrous; pedicels 7–20(–25) by 1–2 mm, usually not thickening towards apex, straight, edges smooth, glabrous (to slightly sericeous); sepals not elongating, reflexed; wall with knobbly surface, thin, lines of dehiscence not elevated; columella 6–11 mm long, fibrous after dehiscence. Seeds 8–12 mm long, 5–9 mm wide, 5–7 mm high; widened seeds not seen.

Distribution — New Guinea.

Habitat & Ecology — Primary lowland (dipterocarp) rain forests. Soil: clay, rocks, ultrabasic soil. Altitude: sea-level to 430 m. Fruiting: March, April, July, August, November.

Note — Typical for the species are the leaves with an obtuse to acute base and a gradually tapering long apex; fruits on short, straight, sturdy pedicels; a thick, fleshy disc, visible after fruit dehiscence.

Figures

Map 2 Distribution of Actephila discoidea Heijkoop & Welzen (■), A. dolichopoda Airy Shaw (▲) and A. emarginata Heijkoop & Welzen (●).

Fig. 2 Actephila discoidea Heijkoop & Welzen (Phyllanthaceae; formerly Euphorbiaceae). a. Habit, note the elongated leaf apices; b. fruit with thick nectar disc; c. apically split stigmas; d. widened seed (left, present when one ovule develops in a locule) and normal seed (right) (a–c: Takeuchi & Towati 14639; d: Sands & Jermy 1244; all L). ― Drawing by Jan van Os, 2016.