556 GRAMINEiE. 



cylindrical, dense ; involucre sessile : bristles setaceous, several or many more than twice as long 

 as the single spikelet ; lowest glume short or usually wholly wanting. — Kth. Rev. t. 39. ^en- 

 chrus, Sw. (P. Richardi and purpurascens, Kth.) : the form with the lowest glume appearing. 

 P. uniflorum, Kth. : the common form with the lowest glume abortive, and the third often de-. 

 void of its palea.— 2'-4' high ; spike 3"-6", longer bristles 6"'-l 2'" long, usually purplish; 

 — Hab. Jamaica (Sw.), on limestone ; S. Kitts !, Els., Dominica !, Imr., S. Vincent, Guild. ; 

 Trinidad !, Cr., in savannahs ; [Mexico ! to Brazil ! ; trop. Africa ! ; East Indies]. 



42. CBNCHRUS, L. 



Character oiPenniselum, but involucre indurated, its scales or bristles united at the base, 

 often spinose, roughened downwards. — Spikelets \-several in each involucre, usually pedi- 

 cellate ; pedicel at length turbinate. 



142. C. echinatus, L. Annual ; involucre about as long as the spikelets : tube inter- 

 nally slit, many-lobed to the middle, pubescent : lobes lanceolate-acuminate : scales several- 

 seriate at the outside of the tute, recurved, middle linear-acuminate, spinescent, lowest 

 shorter, setaceous. — Schreb. Gram. t. 23. — Variable in the length of the spike, the size of 

 the spikelets (2"'-3'" diam.), the length of the lowest glume, the number of the glume- 

 nerves, and in the development of the palea in the <? or neutral flower. 



o. Decumbent ; spike 1 "-1$" long ; involucre small : spines not exceeding the spikelet. 

 — P. pungens, Kth. 



0. viridis, Spreng., C. Mull. Spike H"-3" long; involucre larger: spines stouter, the 

 longest exceeding the spikelet.— C. echinatus, Kth., Sieb. Mart. 17. C. dactylolepis, 

 Steud. 



Hab. Bahamas !, Ejalmars (a) ; Jamaica!, all coll., in savannahs, and along theseacoast ; 

 S. Kitts !, Els. (0), Antigua, Wullschl. (a), Dominica!, Imr. (a) ; Trinidad !, Sch. ; [Mexico ! 

 to Brazil ! ; trop. Africa ! ; East Indies]. 



143. C. tribuloides, L. Annual; involucre exceeding the spikelets: tube ovoid- 

 globose, many-lobed to the middle : lobes and all scales lanceolate-acuminate, the latter 

 several seriate at the outside of the tube, recurved, spinescent : no or few basilar bristles. 

 SI. t. 65./. 1.— C. spinifex, Cav. (Ic. t. 461) : a form with small spikelets. C. platyacan- 

 thus, Anders. : the same with few-nerved glumes. All West Indian specimens agree with 

 this in the small size of the spikelet (2'" diam.), while in the northern, original form the 

 spikelets are usually twice as large : the species however is as variable as the preceding, and 

 often difficult to be distinguished from it. — Hab. Jamaica !, Wils. ; Antigua !, Lane, 

 Wullschl.; Dominica !, Imr. ; [Canada ! to Brazil ! ; trop. Africa ! ; East Indies!]. 



43. ANTHEPHORA, Schreb. 



Character of Cenchrus, but involucre 1 -seriate, 4-5-partite, and lowest glume wanting. 

 An annual grass ; segmeuts of the involucre ovate-lanceolate, acuminate, contracted at the 

 base, including 5-1 spikelets. 



144. A. elegans, Schreb. Gram. t. 44. — Tripsacum hermaphroditum, L. — The West 

 Indian form is glabrous. Spiciform raceme cylindrical, 4"-2" long. — Hab. Jamaica !, -il., 

 March, Wullschl. ; Antigua !, Wullschl. ; Dominica !, Imr. ; Trinidad !, Cr. ; [Mexico ! to 

 Brazil!]. 



44. ARUNDINELLA, Eadd. 



Sterile glumes 3, third with a palea, usually £ . Fertile flower chartaceous, supported 

 by hairs at the base, awned : awn twisted. — Spikelets paniculate : pedicels geminate, un- 

 equal. 



145. A. martinicensis, Trin. Perennial, stout; leaves linear-acuminate, scabrous: 

 sheath hispidulous ; pauicle, dense, erect : inferior branches whorled, compound : spikelets 

 lanceolate ; glumes unequal, 3-5-nerved, second twice as long as the fertile flower ; awn 

 geniculated, twice as long as its entire glume. — A. pallida var. laxa, Ns. ! Ischsemum 

 hispidum martinicense, Kth. — 4'-6' high ; panicle 6"-12", spikelets (the awn excluded) 2 

 long, usually purplish. — Hab. Jamaica!, Pd., Hartw. ; Westmoreland, Hanover, Trinidad, 

 Cr., in swamps ; [French islands ; Panama!]. • 



