Chase — Ax s on Genera of PanicecE. IV. 



145 



Fig. 11. 



Lasiacis divaricatn. 



(Spikelet and fruit x 10 cliam.) 



L. , the type of Grisebach's section. ' ' The author raises Panicum, section 



Lasiacis Griseb. (Fl. Brit. W. 

 Ind. 551. 1S64) to generic 

 rank. The type specimen of 

 Panicum divaricatum L. 

 (Syst. Nat. ed. 10. 2:871. 

 1759 ) was examined in the Lin- 

 naean Herbarium. It was col- 

 lected by Browne in Jamaica. 

 Description. — Inflorescence 

 of open, rarely compact, pan- 

 icles at the ends of the culm 

 and branches; spikelets sub- 

 globose, placed obliquely on 

 their pedicels, the glumes and 

 sterile lemma broad, abruptly 

 apiculate, papery-charta- 

 ceous, shining, many nerved, glabrous, or lanose at the apex only, the 

 first glume rarely over % the length of the. spikelet, somewhat inflated- 

 ventricose, the second glume and sterile lemma subequal or the glume 

 slightly shorter, the lemma enclosing a membranaceous palea and some- 

 times a staminate flower; fruit white, bony-indurated, obovoid, obtuse, 

 both lemma and palea bearing at the apex in a slight crateriform exca- 

 vation, a tuft of woolly hairs, the palea concave below, gibbous above, 

 the apex often free at maturity. Large perennials, usually with freely 

 branching, woody culms, often forming tall half-shrubs; leaf-blades firm, 

 often narrowed to a petiole-like base; a genus of some fifteen species con- 

 fined to the tropics and subtropics of the western hemisphere. 



This genus is unusually well marked, the spikelets particularly of all 

 the species being strikingly similar. 



Besides the species placed in this genus by Hitchcock (Contr. Nat. 

 Herb. 15 : 16. 1910 and Bot. G^az. 51 : 301, 302. 1911) the following North 

 American species, taken from the manuscript revision of the genus 

 Lasiacis, are here transferred : 



- S< 



Lasiacis liebmanniana (Fourn.) Hitchc. 

 Panicum liebmannianum Fourn. Mex.Tl. 2 : 33. 1886. 



Lasiacis oaxacensis (Stead.) Hitchc. 

 Panicum oaxacense Steud. Syn. PI. Glum. 1 : 73. 1854. 



Lasiacis ruscifolia (H. B. K.) Hitchc. 

 Panicum ruscifolium H. B. K. Nov. Gen. & Pp. 1 : 110. 1816. 



Lasiacis rhizophora (Fourn.) Flitchc. 

 Panicum rhizophorum Fourn. Mex. PI. 2:31. 1886. 



Lasiacis procerrima (Hack.) Hitchc. 

 Panicum procerrimum Hack. Oesterr. Bot. Zeitschr. 51 : 431. 1901. 



