Trachymene
(from trachys, rough, and hymen, a membrane; alluding to the channels of the fruit). SYNS. Didiscus, Huegelia. ORD. Umbelliferae. A genus comprising about fourteen species of stove or greenhouse, annual or perennial herbs; one inhabits New Caledonia, another Borneo, and the rest are endemic in Australia. Flowers white or blue, in simple umbels; calyx teeth minute or obsolete; petals entire, obtuse, imbricated; involucral bracts linear, often connate. Leaves ternately dissected or rarely undivided, toothed; stipules wanting. T. coerulea, the only species worth describing in this work, is a rather coarse, erect, more or less hirsute, greenhouse annual or biennial. It should be raised from seeds, sown on a gentle hotbed. T. caerulea (blue). fl. usually blue; petals unequal; involucral bracts numerous, linear; peduncles long, each bearing an umbel of very numerous flowers, 1in. to 2in. in diameter. July. l. once or twice tripartite; lobes linear-cuneate, trifid or incised, acute; upper floral leaves small, simple or trifid. h. 1ft. to 2ft. West Australia, 1827. (B. R. 1225.) SYN. Didiscus caeruleus (B. M. 2875).