Lasianthus brevipedunculatus H.Zhu, 2012

15. Lasianthus brevipedunculatus H.Zhu View in CoL , sp. nov. — Fig. 6 View Fig

Proximus L. nervosus King & Gamble ,sed foliis majoribus 4.5–8 cm longis 2–3 cm latis, cymis brevipedunculatis, floribus 5-meris, lobis calycis triangulatooblongis et pyrenis 5 differt. —

Typus: Nagamasu 3359 (holo L), W Sumatra, Gunung Sago , 2100–2260 m alt., in upper montane forest around the sum- mit, 30 Oct. 1988 .

Shrub, c. 2 m high; branchlets terete, c. 1.5 mm diam, densely brown-yellowish tomentose. Leaves elliptic-oblong to ovate-oblong, 4.5–8 by 2–3 cm, coriaceous, glabrous above, puberu- lous beneath, densely tomentose hairs on midrib and nerves beneath, apex acute or cuspidate, base subrounded, midrib depressed above, prominent beneath, nerves flat or slightly depressed above, prominent beneath, 5 –6 pairs, ascending at an angle of 50–60°, curved to margin, nervules prominent on both surfaces, parallel, margin hirsute; petioles 4–6 mm long, densely tomentose. Stipules triangular, 2 mm long, densely tomentose. Inflorescences shortly peduncled; peduncles 1– 3 mm long, densely tomentose; bracts 1–2, linear, c. 2 mm long, tomentose. Flowers sessile; calyx hirsute external surface, lobes 5, oblong or lanceolate-oblong, 3 mm long, tube very short, less than 1 mm long; corolla 4–5 mm long, tomentose external surface, lobes 5, triangular-oblong, 2 – 3 mm long; stamens 5; ovary with 5 locules. Drupes c. 4 mm diam, sub- globose, subglabrous, crowned by 5 calyx lobes; pyrenes 5.

Distribution — Indonesia (W Sumatra).

Habitat & Ecology — In upper montane forest at 2100 m altitude.

Note — This species is closely related to L. nervosus from Malaysian mountains. It differs from the latter by having rela- tively large leaves (4.5–8 by 2–3 cm), cymes shortly peduncled, flowers 5-merous, calyx lobes triangular-oblong, and drupes with 5 pyrenes. Lasianthus nervosus has leaves of 2.5 – 3.5 by 1.5 cm, cymes sessile, flowers 4-merous, calyx with triangular teeth, and drupes with 4 pyrenes.