Lasianthus brochidodromus H.Zhu, 2012

Zhu, H., Roos, M. C. & Ridsdale, C. E., 2012, A taxonomic revision of the Malesian species of Lasianthus (Rubiaceae), Blumea 57 (1), pp. 1-102 : 21-25

16. Lasianthus brochidodromus H.Zhu , sp. nov. — Fig. 7

Proximus L. membranaceoideus H.Zhu , sed foliis lanceolatis 2–2.5 cm latis, drupis minoribus puberulis obtuse 4–5-porcatis et pyrenis abaxiali leviter verrucosis differt. —

Typus: Gaerlan et al. PPI 23712 ( holo L), Philippines, Luzon, Quezon, Alabat Isl. , 175 m alt., in dipterocarp forest, 25 March 1996 .

Shrub, c. 1.5 m high; branchlets terete, compressed at nodes, c. 1.5 mm diam, glabrous. Leaves: blades lanceolate, glabrous except puberulous nerves and margin beneath, 10 –15 by 2– 2.5 cm; subcoriaceous, apex acuminate, margin slightly undulate and recurved, base acute, midrib slightly prominent above, strongly prominent beneath, nerves prominent on both surfaces, 9–12 pairs, ascending at an angle of c. 90°, curved near margin and joining the nerves above, forming an intramarginal vein (looped venation), internerved vein weak, ascending from the midrib at an angle of c. 90°, combination to the main nerves, nervules conspicuous on both surfaces, reticulate; petioles 1–1.5 cm long, dark, glabrous or sparsely pubescent. Stipules small, subulate, c. 1.5 mm long, pubescent. Inflorescences sessile; bracts absent. Flowers not seen. Drupes in fascicles, sessile, globose, c. 5 mm diam, puberulous, slightly warty, with 4–5 obtuse ridges, crowned by very small calyx teeth; pyrenes 4–5, slightly warty on the abaxial face, orbicular in transverse section.

Distribution — Endemic in Alabat Isl., Quezon, Philippines.

Habitat & Ecology — In dipterocarp forest. Fruiting in March.

Note — This species is characterized by its lanceolate leaves with a looped venation. It seems to be close to L. membranaceoideus , but differs from the latter by having leaves lanceolate, 2–2.5 cm broad, drupes puberulous, c. 5 mm diam, with 4–5 obtuse ridges, pyrenes slightly warty on the abaxial face, orbicular in transverse section. Lasianthus membranaceoideus has leaves oblong, 3–4 cm broad, drupes glabrous, c. 7 mm diam, conspicuously 8-ridged, pyrenes sulcate on the abaxial face, triangular in transverse section.

Figures

Fig. 7 Lasianthus brochidodromus H.Zhu. a. Habit with fruits; b. detail of leaf; c. detail of node showing axillary fruits; d. cross section of fruit (all: F. Gaerlan et al. PPI23712, holo L).