The genus Gyrocheilos W. T. Wang (Gesneriaceae) had 4 species and 2 varieties. It is recorded endemic to China. During the study of specimens and documents of Gesneriaceae of Vietnam, we have found one new occurrence species of Gyrocheilos: G. chorisepalus W. T. Wang for the flora of Vietnam. Gyrocheilos closed to Didymocarpus in stamens confluent at apex and stigma undivided but differ by adaxial lip undivided meanwhile in Didymocarpus adaxial lip 2 lobed.

Gyrocheilos chorisepalus W. T. Wang
1. flowering plant; 2. calyx and stament; 3. fruit
(drawn on specimen VH 5050, HN)
G. chorisepalus W. T. Wang is perennial herb, nearly stemless. petiole 3-8 cm, spreading pubescent, margin double dentate to deeply crenate, peduncle nearly glabrous. Calyx 3-4 mm long, 5 segments equal to unequal. Corolla reddish, ca. 1.0-1.2 cm long, tube ca. 6 mm long, adaxial lip undivided, ca 2.8 mm; abaxial lip 3 lobed, ca. 6 mm. Stamens 2, adnate to corolla ca. 2 mm above base; filaments ca. 3 mm long; anthers ca. 2.5 mm long; staminodes 2, adnate to corolla ca. 2.5 mm above base, ca. 0.8-0.9 mm long. Stigma undivided, head. Capsule 2-3 cm.
Voucher specimens were collected on ridges of the Tamdao mountain in the boundary of two provinces: Thainguyen and Vinhphuc, and deposited in the Herbarium of the Institute of Ecology and biological Resources, Hanoi, Vietnam (HN).
Vu Xuan Phuong
IEBR-VAST
Bio.J.30(1)/3-2008