FLORA OF VIETNAM Rutaceae Zanthoxylum simplicifolium Yang Yi ex Aver., sp. nov.** Ha Giang prov., Quan Ba distr., Bat Dai Son Nature Reserve, Can Ty commune, Lung Vay village, around point 23º06ʹ02.6ʺN 105º03ʹ04.5ʺE, 1200-1305 m a.s.l., karstic, highly eroded mountains composed of solid marble-like limestone, primary evergreen broad-leaved humid forest on steep rocky slopes near mountain tops. Treelet or shrub to 3 m tall on rocky mountain top. Fruits dirty purple. Occasional. 15 April 2018, L. Averyanov, Nguyen Sinh Khang, Chuong Quang Ngan, T. Maisak, VR 219 (holotype – LE 01067292, LE01058154 – photoб isotype – HN). Det. Yang Yi 18 09 2019. The plant differs from all its congeners in obligatory simple leaf.

All photos © L. Averyanov & K.S. Nguyen