Litosanthes gracilis Hayata, Icon. Pl. Formosan.

Litosanthes gracilis Hayata, Icon. Pl. Formosan. View in CoL 2: 113. 1912. Syntype: Botanrosha, G.Nakahara s.n. (n.v.). Fig. 1 View Fig

Shrubs, evergreen, up to 2 m high. Twigs terete, densely hirsute; internodes 1–1.5(–4) cm long. Leaves opposite; blades elliptic or subovate, 1–2.5 × 0.5–1.5 cm, chartaceous, greenish-brown when dry, adaxially glabrous, abaxially puberulent, apex acute, aristate with arista 1–2 mm long, base cuneate, margin entire, midrib slightly prominent adaxially, prominent abaxially, secondary veins 6–10 pairs, ascending at an angle of 60–80° from midrib, curved to the margin, flat adaxially, tertiary veins subparallel; petioles 1–2 mm long, puberulent. Stipules lanceolate, 1–1.5 mm long, puberulent. Inflorescences solitary or cymose, peduncles 0.5–1.5 cm long, puberulent; bracts small, inconspicuous. Flowers pedicellate, pedicels 0.5–1 mm long; calyx campanulate, 1–2 mm long, glabrous, lobes 4; corolla white, 2–4.5 mm long, glabrous outside, triangular-lanceolate, lobes ovate. Fruits drupaceous, obovoid, 3.5–5 mm in diam., glabrous, smooth, black when ripe; pyrenes 4.

Flowering & fruiting: Flowers and fruits were collected in September.

Habitat: Lasianthus biflorus was collected in the semi-shaded understory of semi-evergreen forests at 510–540 m elev., where the species of Lauraceae , Rubiaceae , Myrtaceae , Fagaceae and Fabaceae are dominant.

Distribution: Cambodia, China, Indonesia, Malaysia, Philippines, Thailand, Taiwan and Vietnam. In Laos, this species occurs in the Nam Kading National Protected Area of Bolikhamxai Province in central Laos.

Specimens examined: LAOS, Bolikhamxai Province, Viengthong District, Ban Nadi, Nam Kading National Protected Area , at 515 m, N 18 O 19 ’ 49.401’’ E 104 O 31 ’ 27.655’’, 04.09.2023, Tagane et al. Z367 FOF [ FOF005521 ], KAG [ KAG186811 About KAG ], VMM ); same locality, 05.09.2023, Tagane et al. Z416 FOF [ FOF005571 ], KAG [ KAG186853 About KAG ], VNM [ VNM00072084 View Materials ] ); Khamkeuth District, near Ban Kaengbid , at 537 m elev., N 18 O 13 ’ 9.859’’ E 104 O 30 ’ 21.09’’, 15.03.2024, Tagane et al. Z839 FOF [ FOF005966 ], KAG [ KAG187254 About KAG ], VNM [ VNM00070633 View Materials ] .

Notes: Lasianthus biflorus is a new record for the Flora of Laos. This species is closely related to Lasianthus bifloroideus H.Zhu endemic to Borneo but differs in having twigs densely hirsute (vs. thinly puberulous), cymes with 0.5–1.5 cm long peduncles (vs. sessile or subsessile), and smooth fruit (vs. warty). Among the species of Lasianthus in Laos, L. biflorus is easily recognized by its small size of lamina, which is up to 2.5 cm long and the smallest among the Lasianthus species in Laos, long peduncles up to 1.5 cm long, and ripening black fruits.

Lasianthus hispidulus ( Drake) Pit. In P.H. Lecomte, Fl. Indo-Chine View in CoL 3: 393. 1924; Pham, Fl. Vietnam 3: 205, f. 8523. 2000; Zhu, Acta Phytotax. Sin. 39: 130. 2001; Zhu & Taylor, Fl. China 19: 192. 2011; Zhu et al., Blumea 57: 48. 2012 View Cited Treatment ; Naiki et al., Acta Phytotax. Geobot. 66: 168. 2015; Napiroon et al., Phytotaxa 439: 17. 2020 View Cited Treatment ; Dang & Naiki, Phytotaxa 581: 73. 2023 View Cited Treatment . Mephitidia hispidula Drake, J. Bot. (Morot) View in CoL 9: 239. 1895. Lectotype (designated by Zhu, 2001): VIETNAM, Thai Nguyen Province, Eberhardt 3852 (P).

Lasianthus brevidens Craib, Kew Bull. 1933: 19 View in CoL . 1933. Type : THAILAND, Ratchburi , Prachuap, Khao Luang, 700 m, Kerr 10833 (holo K [ K000777026 !], isotypes BK [ BK257382 View Materials image!], BM [ BM000945605 image!]).