Lasianthus obliquinervis subsp. novoguineensis, H. Zhu

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 : 68

b. subsp. novoguineensis H.Zhu , s ubsp. nov. — Fig. 27

A typo foliis basi asymmetrice cuneatis,stipulis lineari-subulatis 6 mm longis differt. —

Typus: J. Vandenberg et al. NGF.39936 ( holo L), New Guinea, Western Highlands District, 4450 ft alt., in Castanopsis forest, 30 Oct. 1968 .

Shrub, branchlets terete, densely puberulous. Leaves: blades lanceolate to elliptic-lanceolate, 10–15 by 2.5 –5 cm, subcoriaceous, glabrous above, puberulous beneath, apex acuminate, base cuneate and asymmetric, nerves flat above, prominent beneath, 6 –7 pairs, pubescent, nervules conspicuous beneath, parallel. Stipules linear-subulate, 6 mm long, pubescent. Flowers fascicular, sessile; calyx campanulate, densely pubescent, limb with 4–5 triangular lobes; corolla 6–8 mm long, densely hirsute except the base. Drupes globose, hirsute, 4–5 mm diam, crowned by persistent calyx lobes, with 6 obtuse ridges; pyrenes 6, smooth on the abaxial face, ovate in transverse section.

Distribution — Endemic to Papua New Guinea ( Western Highlands).

Habitat & Ecology — In montane forest between 1400–1500 m altitude. Flowering and fruiting between July and October.

Additional specimen examined. New Guinea, Western Highlands, Streimann 8460 (L).

Note — This subspecies differs from the typical subspecies by having leaves with cuneate and asymmetric bases, stipules linear-subulate ( 6 mm long). The typical subspecies has leaves with acute and symmetrical bases, stipules triangular to oblong-triangular.

Figures

Fig. 27 Lasianthus obliquinervis Merr.subsp.novoguineensis H.Zhu.a. Habit with inflorescences;b. detail of node showing stipule and axillary inflorescences; c. calyx split opened; d. corolla split opened; e. fruit; f. cross section of fruit (all: J. Vandenberg et al. NGF.39936, holo L).