252 Mr. D. Don's Descriptions of new Genera and Species 



5-partito ; marginales non radiantes, limbo irregulari, ob 

 laciniam quintam (interiorem) profundi's sejunctam, inde 

 quasi bilabiati : segmentis linearibus, obtusis, subsecundis, 

 canaliculatis, nervis prominulis, summo apice confluenti- 

 bus. Filamenta lineari-angustissima, compressa, glabra. 

 Anthera semi-exsertae, in tubum connatae, appendicular 

 lineari-lanceolatii, obtusa., coriacea, rigidfi, ipsa anther& 

 breviore coronatoe, basi longe biaristatae: aristis lineari- 

 bus, setaceo-acuminatis, canaliculatis, anthera longioribus, 

 aequalibus. Stylus filiformis, basi bulbosus. Stigma mas- 

 culis pentagonum ! obtusum, indivisum ; ligulis tereti-cla- 

 vatum, laeve, exsertum ; fcemineis bipartitum, exsertum : 

 lobis lineari-lingulatis, obtusis, pruinosis, persaspe spira- 

 liter convolutis. Achenia lineari-oblonga, compressa, gla- 

 berrima. Pappus masculis cinereus, caducus : racliis inas- 

 qualibus, paleaceo-setaceis, complanatis, longissimis, den- 

 ticulis spinulosis exasperatis, apice acuto, nunc subpeni- 

 cillato, infra medium flexuosis, simplici tantum ordine 

 digestis ; fcemineis capillaris, persistens, albus : radiis tri- 

 plici serie confertissimis, clenticulato-scabris, longioribus 

 basi latiore subpaleacea. 



Frutices niveo-lanati. Folia alterna, petiolata, integra. Flores 

 terminates, plerumque solitarii, sessiles, magni, purpurei, 

 cernui. 



Nomen a 8ia£ev£is separatio, et generi huic imposuit, ob flores 

 raros esse dioicos in hac familid. 



This is without doubt the most remarkable genus of the whole 

 family. It is dioecious, and, in the structure of the capitula and 

 pappus of the male and female flowers, it differs as much as 

 Antennaria. The male capitula are very much smaller, and 

 besides the male florets of which they are composed, there is a 

 single series of ligulate florets, either with or without pistilla, 



and 



