Scientific name: Lasianthus yaharae V.S. Dang, Tagae & H. TranEnglish name: Vietnamese name: Xú huong yahareOther name:
Type. Vietnam. Klianh Hoa Province, Hon Ba Nature Reserve, near peak, montane evergreen forest dominated by Fagaceae, alt. 1521 m a.s.l., 12°07'06"N, 108°56'51"E, 18 July 2014 Tagane S., Kanemitsu H., Son V.D., Tran H. with Loi X.N., Thach N.D., Dinh N. & Hieu P.N.H. V1741 (holo- type VNM; isotypes FU!, KYO!, Station of Hon Ba Nature Reserve!, VNM!). — Paratype: Vietnam. Klianli Hoa Prov¬ince, Hon Ba Nature Reserve, 30 km west of Nha Trang City, alt. 1521 m a.s.l., 12°07W'N, 108°56'51"E, 2 November 2012 Son V.D., Tagane S., Toyama H., Fuse K.. Naganiasu H„ Hop T, Lam T.T. & Yaliara T. VHB44 (VNM!).
Shrubs, 1-1.5 m tall. Branches and branch- lets solitary, slender, glabrous, blackish when dry. Stipules triangular, 2-3.5 mm long, inner and outer surface strigose. Petiole 5-10 nun long, glabrous. Leaf blade ovate-lanceolate to ovate-elliptic, (8.2—) 12—16 x 3—5(—6) cm, cori-aceous, glabrous on both surfaces except on veins; leaf base cuneate; leaf apex acute to short- caudate, tip pointed, 1-2 111111 long; leaf margin usually reflexed; midrib slightly prominent and glabrous adaxially, strongly prominent and sparsely pubescent abaxially; secondary veins 4-5 pairs, ascending at an angle of ca. 70° from midrib, curved to margin, prominent 011 both surfaces, sparsely pubescent abaxially; tertiary veins prominent on both surfaces, glabrescent, subreticulate. Inflorescences axillary, subses- sile; bracts triangular or broadly to depressed ovate, 2-3 x 2-3 111111 (in fruiting specimens), strigose, hairs brown on both surfaces, margin of outer surface densely hairy, inner surface densely hairy. Flowers sessile. Calyx campanu- late, tube 2-3 mm long, crimson; lobes (4—)5, triangular, 1-1.5 111111 long, minutely strigose. Corolla cylindrical, tube 5-10 mm long, outside tomentose, pinkish; lobes 5, triangular, 2-4 111111 long, outside puberalous, inside villous. Stamens 5; 0.8-1.2 111111 long, anthers oblong. Drupes ovoid, 6-8 111111 long, 5-6 111111 in diam., glabrous except for persistent calyx lobes, reddish brown when ripe; calyx lobes 5, triangular, 2-3 111111 long. Pyrenes 5. Seeds ovoid, ca. 5-6 111111 long, irregular silicate. Flowering from November to January, fruiting from May to July.
DISTRIBUTION AND HABITAT. Hon Ba Nature Reserve, Khanh Hoa Province, southern Viet-nam. In moist evergreen forest, dominated by members of Fagaceae, at ca. 1500111 a.s.l.
Lasianthus yaharae resembles L. dalatensis which is endemic to Dalat, southern Vietnam. However, L. yaharae differs from that species by having fewer secondary veins (4-5 pairs vs. 7-9 pairs), flowers pinkish at anthesis (vs. white), and a larger calyx (2-3 111111 long vs. 1 111111), corolla tube (5-10 111111 long vs. 4 111111 long) and corolla lobes (2-4 111111 long vs. 1.5 111111 long). The leaf surfaces of L. yaharae on both sides have raphides, which are 0.15-0.2 111111 long and visible under a binocular microscope. The density of the raphides on the abaxial surface is higher (more than 200 per cm2) as compared with that in L. dalatensis (25 per cm2).