Lasianthus cailinianus H.Zhu, 2012

18. Lasianthus cailinianus H.Zhu View in CoL , sp. nov. — Fig. 9 View Fig

Proximus L. chrysophyllo Miq. , sed plantis dense patenter fulvi-hirsutis,foliis minoribus oblongis basi leviter asymmetricis, pedunculis cymae robustis 7–8 mm longis, bracteis minoribus apice brevicuspidatis, lobis calycis 5, 2–3 mm longis et pyrenis 5 differt. Similis L. cyanocarpo Jack , sed plantis dense fulvi-hirsutis, foliis majoribus 10–17 cm longis basi abrupte acutis vel subrotundatis,nervis 14-binatis et pedunculis cymae robustis 7–8 mm longis differt.A L. hirsuto (Roxb.) Merr. plantis dense fulvi-hirsutis,foliis basi abrupte acutis vel subrotundatis, nervis 14-binatis, stipulis minoribus 3 mm longis et cymis pedunculatis differt. —

Typus: Ismael 3/ 21.8.1957 (holo L), W Sumatra, east of Pajakumbuh , 500–1000 m alt., in primary forest, 21 Aug. 1957 .

Shrub, c. 2.5 m high, branchlets terete, or slightly compressed in the youngest part, robust, c. 3–4 mm diam, densely spread- ing yellowish hirsute. Leaves: blades oblong, 10 –17 by 3 – 5 cm, thickly chartaceous, stiffly spreading yellowish hirsute on both surfaces, apex acute, base abruptly acute or subrounded, slightly asymmetric, midrib densely stiffly hirsute above, strongly prominent and densely hirsute beneath, nerves depressed above, strongly prominent beneath, densely hirsute, c. 14 pairs, ascending at an angle of c. 80°, curved gradually to margin, nervules obscure above, conspicuous beneath, subreticulate, hirsute, margin slightly recurved, densely hirsute; petioles 5–7 mm long, densely hirsute. Stipules lanceolate-triangular, c. 3 mm long, densely hirsute. Inflorescences pedunculate; peduncles 7–8 mm long, robust, densely yellowish hirsute; bracts 2, leaf-like, ovate, c. 1.5 by 1 cm, with shortly cuspidate apex and rounded or subcordate base, and with midrib and nerves like the leaves, densely yellowish hirsute on both surfaces; bracteoles numerous, outer ones like bracts but smaller, interior ones ovate to linear, c. 1 cm long, densely hirsute; calyx c. 4–5 mm long, densely hirsute, lobes 5, lanceolate, 2 – 3 mm long, densely hirsute on both surfaces; corolla densely hirsute. Drupes c. 4 mm diam, subglobose, densely hirsute, crowned by persistent linear-lanceolate, c. 5 mm long, hirsute calyx lobes; pyrenes 5.

Distribution — Indonesia (W Sumatra).

Habitat & Ecology — In montane primary forest between 500–1000 m altitude.

Notes — This species is characterized by its densely spread- ing yellowish hirsute hairs, peduncled cymes with leaf-like bracts and bracteoles. It is closely related to L. chrysophyllus , but differs from the latter by having branchlets, leaves both surfaces densely spreading yellowish hirsute; leaves relatively small, oblong, with slightly asymmetric base, 10–17 by 3 – 5 cm; peduncles 7– 8 mm long, bracts relatively small with shortly cuspidate apex; flowers 5-merous; calyx lobes 5, 2– 3 mm long. Lasianthus chrysophyllus has branchlets and leaf venation, bracts and calyx densely appressed-pubescent; leaves larger, slightly obovate-oblong, 26–34 by 6–8 cm; peduncles c. 2–3 mm long; bracts larger, with a c. 5 mm long cuspidate apex; flowers 4-merous; calyx lobes 4, c. 1.5 mm long.

It is also related to L. cyanocarpus , but differs from the latter by having plants covered by densely yellowish hirsute, leaves relatively big (10–17 cm long) with abruptly acute to subrounded base and 14 pairs of nerves, cymes with 7–8 mm long robust peduncles. While L. cyanocarpus has much soft pilose hairs on branchlets, leaves and bracts; leaves relatively small (8–13 cm long) with rounded to cordate oblique base and less than 10 pairs of nerves; cymes sessile or subsessile. This species is also similar to L. hirsutus , but differs from the latter by having densely yellowish hirsute hairs, leaves with 14 pairs of nerves and abruptly acute or subrounded base, stipules 3 mm long, cymes peduncled. Lasianthus hirsutus has rusty hirsute hairs, leaves with 7–10 pairs of nerves and acute to cuneate base, stipules 8 –10 mm long, and cymes sessile.