Lasianthus filipedunculatus H.Zhu, 2012

46. Lasianthus filipedunculatus H.Zhu View in CoL , sp. nov. — Fig. 15 View Fig

A L. pendulo Ridl. ramulis foliis subtus pedunculis bracteis molliter tomentosis, costis et nervis supra leviter depressis vel planiusculis, petiolis 5 mm longis, capitulis cymae laxis, floribus 4-meris et pyrenis 4 differt. —

Typus: BRUN 15640 (holo L), Brunei, Temburong, in primary dipterocarp forest, 17 July 1993 .

Treelet; branchlets terete, robust, c. 2 –3 mm diam, brown-yellowish tomentose. Leaves: blades oblong-ovate to ovate, 10–15 by 2.5– 5 cm, chartaceous to subcoriaceous, glabrous above, tomentose beneath, apex caudate to cuspidate, margin recurved, base rounded to subcordate, midrib flat to slightly depressed above, prominent beneath, 4–6 pairs, ascending at an angle of c. 60°, curved to margin, nervules obscure above, conspicuous beneath, subreticulate, tomentose beneath; petioles c. 5 mm long, densely tomentose. Stipules small, triangular, less than 2 mm long, densely tomentose. Inflorescences pedunculate; peduncles slender, 4–13 cm long, tomentose; bracts 2 in each node, thinly linear, 5 –20 mm long, tomentose; bracteoles linear, relatively short, tomentose. Flowers 1–2 in each node, 4-merous, pediceled; pedicels c. 1 mm long; calyx densely tomentose, lobes 4, linear, c. 2.5 mm long, tube short, obconical, c. 1 mm long; corolla c. 3 mm long, upper part external surface tomentose, lower part glabrous; stamens 4. Drupes subglobose, 7–8 mm diam, square in transverse section, warty, sparsely tomentose, conspicuously 4-ridged, crowned by 4 linear tomentose 5 mm long calyx lobes; pyrenes 4, deeply sulcate on the abaxial face, subrhombic in transverse section.

Distribution — Endemic to Borneo: Brunei, Sabah.

Habitat & Ecology — In primary forest of lower montane below 1200 m altitude. Flowering in July and fruiting in November.

Additional specimens examined. Sabah, Nabawan, F. Krispinus SAN 118556 (K, L), F. Krispinus SAN 118646 (K, L); Sabah, Pensiangan, A. Mantor SAN 136779 (L); Brunei, Temburong, D.A. Simpson 2201 (K, L), same locality, P.C. Bygrave 35 (L).

Notes — This species differs from L. pendulus by having soft and relatively short hairs on branches, leaves beneath, peduncles and bracts; leaf midrib and nerves slightly depressed or flat above, petioles c. 5 mm long; head of cymes less compact; flowers 4-merous; drupes with 4 pyrenes. Lasianthus pendulus has relatively long and stiff hairs on branches, leaves beneath, peduncles and bracts; leaf midrib and nerves deeply depressed above; petioles 1–2 mm long, head of cymes more compact; flowers 5-merous; drupes with 5 pyrenes.

This species is also related to L. robinsonii , but differs in having oblong-ovate to ovate leaves, nerves 4–6 pairs, petioles c. 5 mm long and stipules triangular less than 2 mm long. Lasianthus robinsonii has oblong leaves, nerves 8 – 9 pairs, petioles 2 – 3 mm and stipules triangular lanceolate, 4–5 mm long.