Xyloselinum Pimenov & Kljuykov, an edemic genus for Vietnam, consisting of two species, namely Xyloselinum vietnamense Pimenov & Kljuykov and Xyloselinum leonidii Pimenov & Kljuykov. X. vietnamense is a perennial shrub, 1.0-1.5 m tall
leaves are alternate, tripinnate. X. leonidii is also a perennial shrub, 0.8-1.8 m tall
leaves are alternate, tripinnate. Materials for study of X. vietnamense and X. leonidii were collected in Bat Dai Son Nature Reserve, Quan Ba district and Sinh Lung commune, Dong Van district, Ha Giang province. The essential oil yields from leaves and roots of X. vietnamense were different, viz. 0.16 percent in leaves and 0.6 percent in roots (by air-dry material). Main compounds of essential oil from leaves of X. vietnamense were dominated by sabinene (75.0 percent), santalone (5,1 percent), y-terpinene (2.5 percent). Main compounds of essential oil from roots of X. vietnamense were sabinen (36.5 percent), terpinene-4-ol (10.3 percent), Z-p-ocimene (9.7 percent). The essential oil yields from leaves and roots of X. leonidii were 0.15 percent and 0.7 percent respectively (by air-dry material). Main compounds of essential oil from leaves of X. leonidii were sabinene (29.3 percent), p-phellandrene (17.8 percent), myrcene (12.9 percent), a-pinene (7.6 percent). Main compounds of essential oil from roots of X. leonidii were p-pinene (13.7 percent), Z-p-ocimene (12.9 percent), sabinene (10.0 percent) and p-thujene (9.5 percent).