276 CONTRIBUTIONS FROM THE NATIONAL HKBBABITJM. 



spikelet closely appressed to the hollow of the rachis, 4 mm. long, nearly 2 mm. 

 wide, sometimes two borne on a joint, the slender pedicel of the sterile spikelet 

 lying between their inner margins ; first glume acute, smooth, depressed across 

 the base before maturity, not reticulate, pitted, nor winged ; second glume nearly 

 as long as the first, acuminate; sterile lemma hyaline, the fertile lemma and 

 palea much reduced ; pedicel of sterile floret relatively slender, the minute 

 sterile spikelet reduced to two glumes. 



Type in U. S. National Herbarium, no. 950205, collected in pine barren, San 

 Julian, south of Guane, Province of Pinar del Rio, Cuba, December 27, 1916, by 

 Brother Leon (no. 6981). 



In the rather frequent presence of a pair of sessile fertile spikelets at a 

 joint, this species departs from the arrangement typical in Manisuris, an ar- 

 rangement known in but a single anomalous species of the Philippines, Rott- 

 boeUia tri flora Hubbard, belonging to the same group. The above description is 

 drawn from the single specimen cited. It is possible the pair of spikelets is an 

 individual variation. Q/ 



5. Manisuris aurita (Steud.). fc^/vCX/*c ,^RiLO . ^fi-m. - W. 3 *feL&' 



Rottboellia aurita Steud. Syn. PI. Glum. 1: 361. 1854. tSltS 



Tall, like M. impressa, the erect branches with numerous slender racemes 6 



to 10 cm. long, the first glume marginate and winged above, foveolate or pitted 



on the back. 

 Grassy hillsides, Brazil, whence originally described, to Trinidad ; in the 



latter locality known from a specimen in the Gray Herbarium collected by 



Finlay. 



9. jTSTILIX Raf. 



Sessile spikelet perfect, the first glume globose, indurate, alveolate, the 

 adnate rachis joint and pedicel fitting into the opening of the glume ; pedicellate 

 spikelet relatively large, sterile. 



1. Rytilix granularis (L.) Skeels, U. S. Dept. Agr. Bur. PI. Ind. Bull. 282: 

 20. 1913. 



Cenchrus granularis L. Mant. PI. 575. 1771. 



Manisuris granularis Swartz, Prcklr. Yeg. Ind. Occ. 25. 1788. 



Rytilix glandulosa Raf. Bull. Bot. Seringe 1: 219. 1830. 



Hackeloehloa granularis Kuntze, Rev. Gen. PI. 2: 776. 1S91. 



A coarsely hispid, freely branching annual with flat blades and numerous 

 terminal and axillary racemes 1 to 2.5 cm. long. 



A common weed throughout tropical America, introduced from the Old World. 

 Originally described from the East Indies. In the West Indies found on the 

 larger islands and south to Martinique. 



10. TRACHYPOGON Nees. 



Perfect spikelet awned, pedicellate, the pedicel disjointing obliquely, form- 

 ing a sharp callus below the spikelet; staminate spikelet subsessile, persistent 

 on the slender continuous rachis ; racemes solitary or few to several, digitate. 



Awn 10 to 12 cm. long, conspicuously plumose 1. T. gouini. 



Awn mostly not over 5 cm. long, appressed-plumose on the lower part, scabrous 

 above. 



Blades involute ; racemes usually solitary on the culms 2. T. filif olius. 



Blades flat; racemes usually 2 or 3, sometimes solitary 3. T. plumosus. 



