Two New Species of Spiradiclis (Rubiaceae) from China

Abstract

Two new species, Spiradiclis loana R. J. Wang and S. chuniana R. J. Wang, from Guangxi, China, are newly described and illustrated. Spirad- iclis loana is perhaps related to S. spathalata X. X. Chen & C. C. Huang by its oblanceolate, elliptic, or obovate and rosette-like leaves, but distin- guished by its long petioles, fewer secondary veins, and white coronas. Spiradiclis chuniana is probably related to S. tomentosa D. Fang & D. H. Qin by its hairy leaves but distinguished by its truncate leaf bases, long internodes and bracts, short pedicels, and a ring of hair inside the middle of long-styled flowers. The genus Spiradiclis Blumea (Rubiaceae-Hed- yotideae) comprises 31 annual or perennial her- baceous species native to southern and southwest- ern China and northern India (Lo, 1999; Deb & Rout, 1989) and mainly grows in mountainous, es- pecially limestone, areas. It is characterized by a cincinnus cyme, heterostylous and 5-merous flow- ers, and globose, ovoid or linear-oblong dehiscent capsules with four twisted or untwisted valves. Two subgenera, subgenus Sinospiradiclis, characterized by subglobose capsules and untwisted valves when matured, and subgenus Spiradiclis, characterized by ovate or linear-oblong and twisted valves, were recommended (Lo, 1998). An expedition searching for the Spiradiclis species in the Guangxi limestone area was held in 2000 in order to discover more about its biodiversity. In the tribe Hedyotideae, the genus Spiradiclis is very similar and closely related to such Chinese genera as Hedyotis L. (s.l.) and Ophiorrhiza L. in morphological characters, but differs from the for- mer by its 5-merous heterostylous not 4-merous homostylous flowers, and from the latter by its subglobose not obcordate or obconical capsules.