Lasianthus obovatibracteatus H.Zhu, 2012

88. Lasianthus obovatibracteatus H.Zhu View in CoL , sp. nov. — Fig. 28 View Fig

Proximus L. inodoro Blume subsp. pubescenti H.Zhu , sed foliis basi asymmetrice rotundatis,stipulis minoribus,bracteis spathulato-obovatis minoribus, lobis calycis 4 et drupis glabris differt. A L. sterophyllo Merr. foliis minoribus basi asymmetrice rotundatis,stipulis minoribus,bracteis spathulato-obovatis et pyrenis 3–4 differt. — Typus: Beaman 10038 (holo L; iso K), Borneo, Sabah, Lahad Datu, 800–880 m alt., in low mossy primary forest,on ultramafic rock soil, 10 June 1984.

Treelet, c. 2.5 cm high; branchlets terete, c. 2 mm diam, puberulous, darkish. Leaves: blades ovate-oblong, 5 – 8 by 2 – 3 cm, thickly coriaceous, glabrous except puberulous midrib beneath, darkish, apex acute, margin slightly recurved, base rounded or subrounded, slightly asymmetric, midrib slightly depressed above, prominent beneath, nerves prominent on both surfaces, 6–7 pairs, ascending at an angle of 70–80°, curved to the margin, nervules prominent on both surfaces, subreticulate; petioles 5 – 6 mm long, puberulous. Stipules triangular, 3 mm long, subglabrous. Inflorescences sessile; bracts 2, spatulate-obovate, 3 by 2 mm, puberulous or subglabrous. Flowers in fascicle, sessile; calyx campanulate, sparsely puberulous, 4–5 mm long, tubes obconical, 2–2.5 mm long, lobes 4–5, ovate-triangular, c. 2.5 mm long; corolla c. 8 mm long, glabrous outside, lobes 4, ovate-oblong, c. 3.5 mm long, 2.5 mm broad. Drupes ellipsoid, compressed, c. 5 mm diam, glabrous, crowned by 4–5 ovate-triangular calyx lobes; pyrenes 3–4, smooth on the abaxial face.

Distribution — Malaysia (Sabah).

Habitat & Ecology — Low mossy primary forest on ultramafic rock soil. Flowering and fruiting between March and June.

Note — This species is closely related to L. inodorus subsp. pubescens , but differs from the latter by having leaves with rounded and slightly asymmetric base, relatively small stipules, bracts relatively small and spatulate-obovate, drupes glabrous with 3–4 pyrenes. Lasianthus inodorus subsp. pubescens has leaves with cuneate or acute base, stipules 4 mm long, densely pubescent, bracts orbicular and densely pubescent, up to 5 mm diam, calyx lobes 5, drupes pubescent. Lasianthus obovatibracteatus is also similar to L. sterrophyllus , but differs from the latter by having relatively small leaves with rounded and slightly asymmetric base, relatively small stipules, bracts spatulate-obovate, drupes with 3–4 pyrenes. Lasianthus sterrophyllus has leaves 9–12 cm long with acute to subacute base, bracts absent, stipules 4–5 mm long, drupes with 5 pyrenes.