FLORA OF VIETNAM
Annonaceae
Uvaria grandisepala Aver., sp. nov.

Ha Giang prov., Quan Ba distr., Tung Vai commune, Thang village, around point 23°03ʹ41.5ʺN 104°50ʹ41.6ʺE, steep rocky slopes near mountain top composed with eroded stratified highly eroded limestone at elevation 1200-1400 m a.s.l. Primary evergreen broad-leaved very humid forest. Tree about 12 m tall on rocky slope. Flowers light green. Not common. 22 April 2018, L. Averyanov, Nguyen Sinh Khang, Nguyen Tien Hiep, Nguyen Quang Hieu, Chuong Quang Ngan, T. Maisak, VR 701 (holotype – LE01050168, isotypes – HN, LE LE01050084).
New species may be close to U. boniana Finet & Gagnep. and U. tonkinensis Finet & Gagnep. but differs in cuneate leaf base (vs. leaf base rounded to slightly cordate), large sepals 1–1.5 cm long (vs. sepals 3–4 mm long) and large subsimilar green petals 3–4 cm long (vs. sepals purple, 1.5–1.9 cm long, inner petal distinstly smaller than outher).