Phyllanthus dumosus C.B.Rob.

Verwijs, J. I. M., Bouman, R. W. & Welzen, P. C. van, 2019, A taxonomic revision of Phyllanthus subgenus Macraea (Phyllanthaceae), Blumea 64 (3), pp. 231-252 : 238

5. Phyllanthus dumosus C.B.Rob. — Map 5

Phyllanthus dumosus C.B.Rob. (1909) 79; Merr. (1923) 392. — Lectotype (designated here): FB (M.L. Merritt & F.W. Darling) 13974 (K; iso US), Philippines, Luzon , province of Ilocos Norte.

Shrubs, c. 1 m high, monoecious; much-branched with small branches from main stem; branches light brown, terete, not winged, pubescent when young, otherwise glabrous, side branches often shorter than 5 cm; internodes 0.8‒1 mm long. Stipules ovate-triangular, c. 0.4 by 0.2 mm, caducous, flat, membranous, margin thinner than centre, dark brown when dry, base obtuse, margin entire, apex caudate (tip may break off, then rounded). Leaves: petiole 0.2‒0.4 mm long, glabrous; blade ovate-orbicular when young, to elliptic, 2‒7 by 1.5‒3.5 mm, 1.3‒2 times longer than wide, membranous, glabrous, base often oblique, slightly cordate, margin not thickened, revolute, apex slightly retuse to rounded, mucronate, upper side often darker than lower side; midrib slightly raised on lower side, lateral veins 4‒6 per side, barely visible. Staminate flowers 1–2 together, 0.7‒0.8 mm diam; pedicel 1.2‒5 mm long, glabrous, slender; sepals 6, red when dry, in two indistinct whorls, obovate, 0.8‒1 by 0.8‒0.9 mm, apex obtuse or rounded; disc glands 6, flat, slightly ovoid with broad end towards stamen, c. 0.2 by 0.1 mm, c. 0.1 mm high, smooth; stamens 3, c. 0.4 mm long, filaments free, reflexed, thecae rounded to oval, 0.2‒0.3 mm long. Pistillate flowers usually solitary, c. 1.5 mm diam when closed, c. 3 mm diam when opened; pedicel c. 2 mm long, glabrous, slender; sepals 6, in two indistinct whorls, obovate, 0.8‒1.2 by c. 0.7 mm, midrib not conspicuous, apex obtuse to acute; disc glands 6, elliptic, partly covered by ovary, only orbicular glands visible, c. 0.3 by 0.1 mm, smooth; ovary sessile, globose, 6-grooved, c. 1 mm diam, 0.6‒0.7 mm high, glabrous; style absent, stigmas 3, 0.3‒0.4 mm long, bifid for two third of length. Fruits subglobose, 2.5‒3.5 mm diam, 6-grooved, brown when dry, glabrous; pedicel 8‒12 mm long; columella c. 1.5 mm long. Seeds 1.7 mm long, verrucose-tuberculate along longitudinal lines ( Robinson 1909).

Distribution — Philippines (Luzon, Ilocos Norte Prov., Mount Piao).

Habitat & Ecology — Exposed ridges ( Robinson 1909). Altitude: c. 1100 m. Flowering and fruiting in November, only known from the type.

Notes — 1. Very similar to P. chrysanthus , but differing in the size of the shrub stems and pedicel lengths of the flowers of both sexes.

2. Only the type material is available and this species has not been collected since. The type only contains a few fruits and no seeds. Since the description by Robinson (1909) seems adequate, the species is incorporated here.

Figures

Map 5 Distribution of Phyllanthus dumosus C.B.Rob. (●), P. everettii C.B.Rob. (▲) and P. samarensis Müll.Arg. (■) in the Philippines.