Trilisa
(from trilix, triple; in allusion to the divisions of the pappus). ORD. Compositae. A small genus (two species) of hardy, erect, perennial herbs, natives of North America. Flower-heads purplish or white, rather small, paniculate; florets equal, regular, tubular, five-cleft; involucral bracts in two or three series; receptacle flat, naked. Leaves alternate, entire, amplexicaul; radical ones elongated. Only one species calls for description here. It thrives in any moderately good, light soil. Propagation may be effected by divisions, in spring; or by seeds, which are usually sown early in autumn.
T. odoratissima (very odorous). Vanilla Plant. fl.-heads bright purple, numerous, pedicellate; involucral scales glandular. September. l. thick; radical ones large, obovate-spathulate, tapering at base, often slightly and obtusely toothed; cauline ones oblong, clasping at base, the upper ones small and scattered. Stem 2ft. to 4ft. high, corymbose at top. 1786. The leaves, when bruised, exhale the odour of vanilla. SYN. Liatris odoratissima (A. B. R. 633; S. B. F. G. ser. ii. 184).