Heteroblemma alternifolium (Blume) Cámara-Leret, Ridd.- Num. & Veldk. 2013

Cámara-Leret, R., Ridder-Numan, J. W. A. & Veldkamp, J. F., 2013, Revision of Heteroblemma gen. nov. (Dissochaeteae - Melastomataceae) from Malesia and Vietnam, Blumea 58 (3), pp. 229-240 : 234

1. Heteroblemma alternifolium (Blume) Cámara-Leret, Ridd.- Num. & Veldk. , comb. nov. — Fig. 1 , 2I

Medinilla alternifolia Blume, Mus. Bot. 1 (1849) 19. — Lectotype: Korthals s.n. ‘ Indrapura ’ (holo L, sh. no. 908.129-1597), partly designated by Bakhuizen van den Brink Jr (1943, 1946, 1947: 177, ‘ Blume s.n. ’), sheet number selected here.

Medinilla scandens King (1900) 60. — Lectotype: King’s Collector 1814 (holo CAL; BM), designated here.

Innovations glabrescent. Branchlets striate to pustulate, glabrous. Petioles terete, 3.5–29 cm by 2–5 mm, glabrous (rarely pilose). Leaves elliptic to lanceolate, 9–32 by 6–16.5 cm, 1.1–4 times as long as wide, 1–4 times as long as the petioles, base acute, margin entire or laxly serrulate, glabrous or ciliolate, apex acuminate, pergamentaceous (i.s.), underneath glabrous, 5–9-plinerved, basal acrodromous, first pair of primaries 2–10 mm away from the base, distalmost primaries 1–100 mm away from the preceding pair, submarginal vein conspicuous, secondary nerves conspicuous, angle of divergence from midvein acute wide, tertiary nerves conspicuous. Bracts 1–2 mm long. Flowers born on fascicles on old wood, pedicels 5 – 20 mm long, glabrous (rarely pilose). Mature floral buds 8 –10 by 3–4 mm. Hypanthium urceolate to campanulate, 3 – 4 mm long, glabrous (rarely pilose). Sepals 0.5–1.5 mm long, teeth absent or minute, 0–0.5 mm, apex glabrous. Petals 5–6 mm long, white, pink, or violet, outside finely papillose. Filaments 1.5–3 mm long. Anthers 4 –5 mm long, lateral appendages not recurved, 0.25–0.4(–2) mm long, dorsal spur triangular to lanceolate, 1–1.5 mm long. Style 5–7 mm long, glabrous to papillose. Fruit 7–9 by 6–7 mm, glabrous (rarely pilose), calyx teeth inconspicuous or absent; pedicels in fruit 5– 30 mm long, glabrous (rarely hirsutulous); inside filled with jelly.

Distribution — Vietnam (Thua Thiên-Huê), Peninsular Malaysia (Johor, Pahang, Perak, Terengganu), Sumatra (widespread), Borneo (widespread), Celebes (Upper Sopu Valley).

Habitat — Primary mixed dipterocarp forest, secondary forest, marshy forest, fresh water swamp forest, near water, along river side, on sandy clay, loam, sandstone, sometimes ultramafic, 0–1100 m altitude.

Collector’s notes — Succulent twining climber with roots, becoming lianaceous, vine, up to 15 m high. Innovations purplish, bronze. Stems, twigs grey brown, brownish, leaves apparently on short shoots, growth in length apparently by other stems with more distant leaves (Stevens et al. 521). Young leaves opposite, very anisophyllous, older ones apparently alternate. Petioles thick-fleshy-juicy, pale green, purplish reddish. Leaves mid-green above, beneath reddish purple becoming pale green, deeply ribbed, nerves reddish, bullate between the nerves. Inflorescences cauliflorous, deep pinkish red. Peduncles green, red. Pedicels yellowish green. Hypanthium pink, red, reddish green, yellowish green. Petals white, pinkish (especially at the tips), pink lilac, violet. Filaments white, anthers creamy yellow, yellow, appendage undulately margined. Styles white. Stigma yellowish, bright red. Fruits berries, dirty pale greenish, yellowish green, pale yellow, yellow, lemon yellow, greenish orange, orange, reddish orange, bright red.

Notes — The best collected species of the genus, it presents great variability in the morphology of the leaves and the reported colour of the fruits, whereby the ‘fruits’ clearly are hypanthia from which the petals and stamens had dropped off.

From Celebes there is only one collection (Van Balgooy 3531) and it has hirsutulous pedicels but otherwise it falls within the variability of the species. From Vietnam there is only one collection (Poilane 29857) found in the Thua Thiên-Huê area, with the longest lateral appendages of all H. alternifolium collections (up to 2 mm).

It differs from H. cordatum in the leaf with an acute base, basal acrodromous venation, and the glabrous underside.

107 collections were seen.

Figures

Fig. 1 Heteroblemma alternifolium (Blume) Cámara-Leret, Ridd.-Num. & Veldk. Transverse section through stele (Achmad 355, L). — Scale bar = 1 mm.

Fig. 2 Examples of some hypanthia. a. Heteroblemma barbatum (BW 8404 (Vink)); b. H. capillipes (S. 36279 (Ilias Paie)); c. H. serpens (Ridley July 1893); d. H. coronatum (SAR 25080 (Banyeng ak Nudong)); e. H. clemensiae (Clemens 3829); f. H. kemulense (Endert 4330); g. H. loratum (Haviland 1682); h. H. flagellatum (Haviland 68); i. Heteroblemma alternifolium (Soedarsono 378). — Scale bar = 1 mm.