6. Begonia vivipara Aver., Nuraliev & Y.M.Shui, sp. nov. (Fig. 6)

B. sect. Platycentrum (Klotzsch 1855: 243) de Candolle (1859: 134).

Diagnosis:— Remarkable in producing bulbils at junction of petiole and leaf blade; most close to B. longialata K.Y.Guan & D.K.Tian (2000: 132), differing in petiole 5–10 cm long, shallowly lobed leaf blade 8–12 cm long and wide and setose on both sides and margin, staminate flowers with pedicel 12–22 mm long and tepals subequal in length, pistillate flowers with pedicel 0.4–1.2 cm long and with 4 tepals, styles 2.2–3 mm long. Also the new species is similar to B. macrotoma Irmscher (1951: 41), differing in its abaxially hairy leaf blade, glabrous peduncle, abaxially glabrous outer tepals of staminate flowers and all tepals of pistillate flowers, staminate flowers with outer tepals 10–15 mm long and 16–21 mm wide, pistillate flowers with 2 or 3 styles.

TYPE:— LAO PDR. Champasak Province: at the base of Tad Tayicseau Waterfall, 15°05’02.9’’N 106°35’28.8’’E, at elevation 725 m a.s.l., lithophyte on stream rocks along shady river slopes, 07 December 2017 , E. Konstantinov, T. Vongsa, K 418 (holotype LE: LE01057897 http://en.herbariumle.ru/?t=occ&id=8387) .