Lasianthus pseudolongifolius 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 : 75-77

99. Lasianthus pseudolongifolius H.Zhu , sp. nov. — Fig. 32

Similis L. longifolio Wight , sed stipulis minoribus,lobis calycis 4–5, oblongis, 4–5 mm longis, 2.5 mm latis, tubo calycis 3 mm longo differt. —

Typus: Bernard Lee S.39988 ( holo L), Borneo, Sarawak, Sg. Nawai , 800 m alt., on sandstone soil, 5 Sept. 1978 .

Shrub, 2.5 m high; branchlets robust, 0.5 mm diam, glabrous; lenticels conspicuous. Leaves: blades oblong, 20– 32 by 6 –10 cm, coriaceous, glabrous on both surfaces or sparsely puberulous on nerves beneath, brown when drying, apex cuspidate, margin recurved, base acute; midrib depressed above, prominent beneath, nigrescent, nerves slightly prominent above, strongly prominent beneath, 10 –12 pairs, ascending at an angle of 70–90°, curved to the margin, nervules prominent on both surfaces, reticulate; petioles 5 –10 mm long, glabrous. Stipules triangular, 4–5 by 4–5 mm, glabrous. Inflorescences axillary, sessile; bracts inconspicuous or small, triangular, 1– 2 mm long. Flowers fascicular, sessile; calyx 7– 8 mm long, thinly puberulous outside, lobes 4–5, oblong, 4–5 mm long, 2.5 mm broad, rounded or obtuse at apex; corolla c. 1 cm long, glabrous outside, lobes 4–5, ovate, thinly puberulous external surface, floccose internal surface. Fruits not seen.

Distribution — Endemic to Borneo ( Sarawak).

Habitat & Ecology — In primary forest near stream bank between 800–1000 m altitude. Flowering between December and March.

Additional specimen examined. Sarawak, G.H. Pickles 3673 (L).

Note — This species looks like L. longifolius except the quite different flowers and relatively small stipules. It has a calyx divided into clear lobes; calyx lobes 4–5, oblong, obtuse or rounded at apex, 4–5 mm long, 2.5 mm broad; calyx tube 3 mm long; stipules triangular, 4 by 4 mm. Lasianthus longifolius has calyx with an enlarged cupular limb and truncate apex; stipules up to 1 cm long.

Figures

Fig. 32 Lasianthus pseudolongifolius H.Zhu. a. Habit with inflorescences; b. flower; c. calyx; d. corolla split opened (all: Bernard Lee S.39988, holo L).