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Malesian Euphorbiaceae Descriptions |
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Welzen, P.C. van, R.A. Banka & C.D. Leoncito. 1993. A Revision of the Malesian monotypic genus Cheilosa Blume (Euphorbiaceae). Blumea 38: 161166.
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Cheilosa Blume, Bijdr. (1825) 613; Pax in Engl. & Prantl, Nat. Pflanzenfam. 3, 5 (1890) 90; Pax & K.Hoffm. in Engl., Pflanzenr. IV, 147, 4 (1912) 12; 14 (1919) 50; Back. & Bakh. f., Fl. Java 1 (1963) 496; Whitmore, Tree Fl. Malaya 2 (1973) 77; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 68; Kew Bull. 36 (1981) 276; Welzen, Banka & Leoncito, Blumea 38 (1993) 162; Radcl.-Sm., Gen. Euphorbiacearum (2001) 120; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11 (2014) 105. Type: Cheilosa montana Blume
Tree, dioecious, base fluted; branchlets with relatively wide pith. Stipules early caducous. Leaves alternate, simple; petiole basally and apically pulvinate; pulvinus often with transverse grooves; blade symmetric, not punctate, without exudate; base cuneate to emarginate; margin dentate to crenate, with abaxially gland in every tooth; apex rounded to obtuse (to acuminate); lower surface with simple and often with fascicled hairs, glabrescent; venation pinnate, looped at the margin with a vein from every loop to the gland. Inflorescences ramiflorous to axillary to terminal, thyrsoid with 1 to several branches per axil; branches flat, usually unbranched; cymules mono- to dichasial, with 13 flowers; bracts to the cymules often leaf-like; bracts to the flowers often with two basal extensions as if bracts and bracteoles are united. Flowers actinomorphic; pedicels elongating in fruit; sepals 5 (or 6), free, ovate, imbricate, thin to coriaceous, margin often membranous, sericeous, glabrescent, long resistent in fruit; petals absent; disc annular, flat, more or less 5-lobed, hirsute, resistent in fruit. Staminate flowers with 9 or 10 stamens in 2 whorls; filament flattened, glabrous; anther basifixed, opening latrorsly lengthwise, glabrous; connective often slightly elongated; pistillode with (2 or) 3( or 4) free, hirsute remnants of the carpels. Pistillate flowers without stamens; ovary 3- (to seldom 4)-locular; 1 ovule per locule, descending, epitropous, anatropous, subapically attached to column; style short; stigmas 3, spreading outwards, upper surface papillate, apically split apart and recurved. Fruits rhegmas, ovoid (to globular), slightly triangular in transverse section, outside smooth, tomentose, inside smooth, glabrous; column left after dehiscence; mesocarp woody, cork-like in appearance; septa complete. Seeds 13 per fruit, ovoid with a convex abaxial surface and a V-shaped, almost flat adaxial surface, both surfaces with longitudinal keel in the center; aril surrounding seed completely, adnate to seed; endosperm present, with a central longitudinal, flat embryo.
Distribution As the species.
Cheilosa montana Blume, Bijdr. (1825) 614; Pax & K.Hoffm. in Engl., Pflanzenr. IV, 147, 4 (1912) 12, fig. 3; S.Moore, J. Bot. Brit. For. 63 (1925) 104; Back. & Bakh. f., Fl. Java 1 (1963) 496; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 68 (sub Ch. malayana); Welzen, Banka & Leoncito, Blumea 38 (1993) 163, Fig. 1, 2. Type: Blume s.n. (L, holo, sheet no. L.903.155-415; iso in BM, F, L, NSW, P, US, Z), Indonesia, Java.
Baliospermum malayanum Hook.f., Fl. Brit. India 5 (1888) 463; Ridl., Fl. Malay Pen. 3 (1924) 313. Scortechinia malayana Ridl., Fl. Malay Pen. 5 (1925) 332, in note. Cheilosa malayana Corner ex Airy Shaw, Kew Bull. 16 (1963) 364; Kew Bull. 20 (1966) 49; Whitmore, Tree Fl. Malaya 2 (1973) 77; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 68; Kew Bull. 36 (1981) 276. Type: Maingay KD 1455 (K, holo), Peninsular Malaysia.
Cheilosa homaliifolia Merr., Philip. J. Sci., Bot. 8 (1913) 379; Pax & K.Hoffm. in Engl., Pflanzenr. IV, 147, 14 (1919) 50; Merr., En. Philip. 2 (1923) 457. Type: Wenzel 147 (PNH, ; iso in A, F, G, MO, NSW, US), Philippines, Leyte, Dagami.
Cheilosa spec.: Merr., J. Str. Br. Roy. As. Soc., spec. issue (1921) 346. (pro Villamil 31, n.v., Borneo, Sabah = British North Borneo).
Cheilosa homaliifolia Merr. var. grandifolia Merr., En. Philip. 2 (1923) 457. Type: BS (Ramos & Edaρo) 37282 (PNH, holo, ; iso in K), Philippines, Mindanao, Zamboanga Distr., Malangas.
Cheilosa montana Blume var. longifolia S.Moore, J. Bot. Brit. For. 63 (1925) 104. Type: Forbes 1839 (BM, holo; iso in L), Indonesia, Sumatra, Lampongs, Mt. Tengemoes.
Baccaurea malayana auct. non King ex Hook.f.: Hook.f., Fl. Brit. India 5 (1887) 374, excl. Hedycarpus malayanus Jack; Boerl., Handl. Fl. Ned. Indiλ 3, 1 (1900) 280, in note; Pax & K.Hoffm. in Engl., Pflanzenr. IV, 147, 15 (1922) 70; Ridl., Fl. Mal. Pen. 3 (1924) 247; Burkill, Dict. Econ. Prod. Malay Pen. 1 (1935) 279; Corner, Gard. Bull. Str. Settl. 10 (1940) 290 (conclusion). See note in Airy Shaw (1963: 364).
Tree, up to 28 m high by 50 cm d.b.h. Outer bark grey-brown to brown, rather smooth; inner bark orange-brown; slash smelling like fresh sugar-cane; exudate white; wood white (to yellow). Branchlets rounded, smooth to somewhat rough, glabrescent; flowering twigs 211 mm thick. Stipules triangular, 11.7 by 0.60.8 mm, sericeous. Leaves: petiole 0.78.5 cm long, round to dorsoventrally flattened; blade ovate to obovate, 5.632.5 by 2.816 cm; base narrowly cuneate to emarginate; margin shallowly (to deeply) laxly dentate to crenate, flat; apex rounded to obtuse (to acuminate), very apex rounded (to mucronulate); upper surface smooth, glabrous; lower surface smooth, simple hairs somewhat sericeous (to hirsute: see note), glabrescent, fascicled hairs usually present especially near midrib; venation with 69 pairs of opposite to alternate nerves, tertiary veins partly scalariform, other veins widely reticulate. Inflorescences: branches 0.517 cm long, sericeous; bracts to cymules elliptic to obovate, 1.46 by 0.71.8 mm, coriaceous, apex rounded to acute, sericeous on both sides; bracts to the flowers triangular, 0.71.5 by 0.42 mm, subglabrous to sericeous. Peduncles 0.72.3 mm long, in fruit up to 8 mm long, short sericeous to glabrescent. Staminate flowers 2.23.5 mm in diam, greenish; sepals 11.5 by 0.61.3 mm; filaments 0.52.8 mm long; anthers 0.40.8 by 0.30.7 mm. Pistillate flowers c. 5 mm in diam.; sepals 1.53.2 by 1.22 mm; ovary ovoid, 24 mm high, hirsute; style c. 0.5 mm long, hirsute; stigmas 3, 1.11.7 mm long, upper surface glabrous, split part 0.51.2 mm long. Fruits 1 to 5 per inflorescence branch, 2.25.2 by 24.3 cm, velvety greenish grey; wall 1.56 mm thick. Seed 1.53.3 by 1.42.2 by 0.81.3 cm, black; aril up to 1.5 mm thick, outside orange, inside yellow, oily; embryo 9.519 by 815 mm, white; plumule and radicle 24 mm long.
Distribution Malesia: Malay Peninsula (incl. Singapore), Sumatra, W Java, Borneo, S Philippines.
Habitat & Ecology Primary and hill forest, swamp forest, along rivers, on ridges. Soil: yellow clay to red sand. Alt.: 51200 m. Flowering: February, June to November; fruiting: April to October. Some branches hollow due to insects.
Vernacular names Malay Peninsula, Selangor: nawe, jahakah. Sumatra, Palembang area: betih rawang. Borneo, around Balikpapan: kepajang hutan, ketapi danau.
Note Burley, Tukirin et al. 2478 (Borneo) and BS 37282 (Philippines) show subhirsute leaves. All other specimens are subglabrous or slightly sericeous.
Cheilosa whiteana Croizat, J. Arn. Arbor. 23 (1942) 507; Airy Shaw, Kew Bull. 16 (1963) 365, in note. Type: FB (Curran) 17733 (A, holo), Philippines, Luzon, Prov. of Pampanga, Mt. Arayat. = Trigonostemon whiteanus (Croizat) Airy Shaw, Kew Bull. 38 (1983) 68.
Note: The species is only known from the type specimen. The latter only possesses a few withered pistillate flowers. The species differs from Cheilosa by having two basal glands on the upper surface of the leaf-blade (absent in Cheilosa), the presence of petals (absent in Cheilosa), and hardly split stigmas (deeply split in Cheilosa). The leaves also show a rather strongly trinerved leaf-base. The transfer to Trigonostemon is still doubtful as strongly ovate, crenate leaves are rare in this genus.
