elms, — Notes on Genera of Panice&. IV 



145 



Fig. 11. 



Lasiacis divaricata. 



(Spikelet and fruit x 10 diam.) 



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



Lasiacis Griseb. (Fl. Brit. W. 

 I ml. 551. 1S64) to generic 

 rank. The type specimen of 

 Panicum divaricatum L. 

 (Syst. Nat. eel. 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 3-3 the length of the spikelet, somewhat inrlated- 

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

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

 times a staminate (lower; 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 irw at maturity. Large perennials, usually with freely 



branching, w ly 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 i< 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. Gaz. 51:301, 302. 1911) the following North 

 American species, taken from the manuscript revision of the genus 

 Lasiacis, are here transferred : 



Lasiacis liebmanniana (Fourn. ) Hitchc. 

 Panicum liebmannianum Fourn. Mex. PI. 2 : 33. 188(3. 



Lasiacis oaxacensis (Steud. ) Hitchc. 

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



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

 Panicum ruscifolium H. B. K. Xov. Gen. A: Sp. 1 : 110. 1816. 



Lasiacis rhizophora (Fourn.) Hitchc. 

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



Lasiacis procerrima (Hack.) Hitchc. 

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



