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Malesian Euphorbiaceae Descriptions |
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Welzen, P.C. van. 1998. Revisions and phylogenies of Malesian Euphorbiaceae: Subtribe Lasiococcinae (Homonoia, Lasiococca, Spathiostemon) and Clonostylis, Ricinus, and Wetria. Blumea 43: 131164.
Welzen, P.C. van & S.E.C. Sierra. 2005. Lasiococca brevipes (Euphorbiaceae): a new combination. Blumea 50: 275277.
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Lasiococca Hook.f., Hook Icon. Pl. 16 (1887) pl. 1587; Fl. Brit. Ind. 5 (1887) 456; Pax in Engl. & Prantl, Nat. Pflanzenfam. III, 5 (1890) 72, fig. 43; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.xi (1919) 118, fig. 28; in Engl. & Harms, Nat. Pflanzenf. ed. 2, 19c (1931) 149, fig. 76; Airy Shaw, Kew Bull. 16 (1963) 358; Kew Bull. 21 (1968) 406; Whitmore, Tree Fl. Malaya 2 (1973) 104; Thin, Biol. J. Hanoi 8 (1986) 36; Thin, Duc & Welzen in Welzen, Blumea 43 (1998) 141; Radcl.-Sm., Gen. Euphorbiacearum (2001) 237; Welzen & S.E.C.Sierra, Blumea 50 (2005) 275; Welzen in Welzen & Chayam., Fl. Thailand 8, 2 (2007) 351; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11 (2014) 129. Type: Lasiococca symphylliifolia (Kurz) Hook.f.
Shrubs to trees, presumably monoecious, but sexes flowering at different times; bark pale, deeply fluted, buttressed; flowering twigs smooth, glabrous except on nodes. Indumentum existing of simple hairs only except for glandular hairs on bracts and sepals in the pistillate flowers of L. symphylliifolia. Stipules triangular, outside hairy, inside glabrous, early caducous. Leaves spirally arranged, in pseudo-whorls or subopposite, simple; petiole short, reniform, completely pulvinate; blade chartaceous, usually symmetric, base narrowly cordate, margin entire, wavy, with glands in the margin or on the upper surface along the margin in the lower third of the blade, apex cuspidate, very apex rounded, usually green when dry, somewhat paler below, nerves looped and joined near margin, with hair dot domatia in L. malaccensis, veins scalariform, quaternary veins reticulate. Inflorescences: staminate flowers in solitary axillary racemes, unbranched, flattened, one flower per node; pistillate flowers single in the axils. Bracts and bracteoles: in staminate flowers broadly ovate, forming cup under each single flower, bracts outside hairy, bracteoles subglabrous, keeled; in pistillate flowers triangular, subglabrous, caducous. Flowers actinomorphic, petals and disc absent, odour unknown. Staminate flowers shortly pedicelled; sepals 3, subglabrous to glabrescent, with c. 4 obvious nerves; stamens more than 100, very small, united into 47 androphores, latter bifurcating into separate stamens; anthers 2-locular, opening introrsely with lengthwise slits; pistillode absent. Pistillate flowers: pedicel very long, with abcission zone in upper part; sepals 5, leaf-like, subglabrous, reflexed in fruit; pistil 3-locular, lobed in transverse section, one ovule per locule, papillate, puberulous, with one or several bristle hairs; style short, hairy, stigmas 3, apically not split, hairy below, above with flat, broad papillae. Fruits slightly lobed capsules, outside puberulous, echinate, woody, thin-walled, septicidally breaking into 3 bivalved parts; column after dehiscence with a narrow, straight, non-fibrous septum margin and a broadened apex, obtriangular in longitudinal section. Seeds usually 2 or 3 per fruit, obovoid, slightly triangular in transverse section; caruncle or arilloid absent; embryos not seen.
Distribution --- Three species: L. symphylliifolia (Kurz) Hook.f. is restricted to India (Bihar, Sikkim), L. comberi Haines ranges from India (Madras, Orissa) to N. Vietnam (Ha Son Binh, Lang Son) and China (Hainan), and only L. brevipes (Merr.) Welzen & S.E.C.Sierra is found in Malesia (Malay Peninsula, Sulawesi, Lesser Sunda Islands).
Habitat & Ecology --- Small to relatively large trees, in scrubs or semi-evergreen forest. Soil: sand and perhaps other types. Alt.: 601200 m. Flowering: April to August, fruiting: July to August.
Lasiococca brevipes (Merr.) Welzen & S.E.C.Sierra, Blumea 50 (2005) 276. Mallotus brevipes Merr., Philipp. J. Sci., Bot. 9 (1914) 487; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.xiv (1919) 19; Merr., Enum. Philipp. Fl. Pl. 2 (1923) 432; Airy Shaw, Alph. Enum. Euphorb. Philipp. Isl. (1983) 35. Type: R.S. Williams 2968 (holo PNH; iso NY, 2 sheets), Philippines, SE Mindanao, Davao Prov., between Digas and Santa Cruz.
Lasiococca malaccensis Airy Shaw, Kew Bull. 21 (1968) 406; Whitmore, Tree Fl. Malaya 2 (1973) 104; Thin, Duc & Welzen in Welzen, Blumea 43 (1998) 142, fig. 3, Map 2. --- Type: SF (Kiah) 37231 (SING, holo, n.v.; iso in K, n.v., L), Peninsular Malaysia, Malacca, Batang Malakka Forest Reserve.
Lasiococca sp.?: Airy Shaw, Kew Bull. 37 (1982) 26, pro bb 26278 (L), Celebes, Ond. Kolaka, Mala-mala.
Tree up to at least 8 m high; flowering twigs c. 2 mm thick. Bark smooth, whitish. Stipules c. 2.3 by 0.9 mm. Leaves: petiole 14 mm long, subglabrous; blade obovate, 820 by 2.65.7 cm, ratio 33.5, on both sides smooth, glabrous except for hair tuft domatia on lower surface in axils of veins, venation raised on both sides, especially below, with 912 pairs of nerves. Staminate inflorescences up to 3 cm long; bracts broadly ovate, c. 1 by 1.3 mm; bracteoles elliptic, c. 0.8 by 0.3 mm. Staminate flowers c. 5.5 mm in diameter; pedicel c. 1 mm long; sepals c. 3.4 by 1.9 mm; androphores up to 4.5 mm long, anthers c. 0.3 by 0.5 mm. Pistillate flowers: bracts and bracteoles caducous; pedicel 0.87 cm long, (sub)glabrous; flowers 11.3 cm in diameter; sepals 4 or 5, elliptic, 3.28.2 by 13.8 mm, apex cuspidate, subglabrous; pistil c. 3.5 by 2 mm; style 0.51.2 mm long; stigmas c. 1.8 mm long. Fruits c. 6 by 5 mm, thin-walled; column 4.54.8 mm long. Seeds ellipsoid but flattened adaxially, c. 4.8 by 4 by 3.5 mm.
Distribution Very disjunct in Malesia: Malaysia (Malacca), Philippines (Mindanao), Sulawesi (Sulawesi Tenggara), and Lesser Sunda Islands (Flores).
Habitat & Ecology Apparently a very rare species. In Malaysia on hill slopes. Flowering: March to June; fruiting: June.
Vernacular name Philippines: Talag (Magindanαo; Merrill, 1923). Lesser Sunda Islands: Flores: Mborong.
Note Philippine specimens with more hairy branches and petioles, usually smaller and relatively broader leaves, shorter pistillate pedicels and sepals.
