AGROSTIDE.E. 275 



long, 3-5 mm. broad. Sterile rudiments of spikelets numerous, 

 ciliate, empty glumes eiliute, bristles about as long as the florets; 

 floral glume oval, 3 mm. long, the awn 2-20 mm. long; palea 

 nearly as long as its glume. 



Mexico, Frin(jJe 4G0G ; also found in Panama. 



Dry sliaded ledges. 



55. (120.) Heleochloa Host, Gram. 1:23, t. 29, 30 (1801). 

 Cri/psis Lam. Tabl. Encycl. 1 : 166 (1791), not Ait. Pechea Pour. 

 Chlor. Narb. ex Kunth, Enum. PI. 1: 22 in Syn. (1833). Ehizo- 

 cephalus Boiss, Diagn. (I.) 5:68 (1844); 13:43 (1853). 



Spikelets with one perfect flower crowded in a spike or dense- 

 spikelike panicle which is sometimes partially included in the 

 enlarged sheath of the upper leaf, rachilla subarticulate above the 

 lower persistent glumes and not extended beyond the flower. The 

 2 empty glumes slightly unequal, membranous, acute, conduplicate, 

 awnless, with a keel more or less ciliate ; floral glume similar. j)er- 

 haj)S a little longer ; palea shorter, hyaline, emarginate or 2-lobed,. 

 very delicately 2-nerved, or keeled. Stamens 3. Styles distinct. 

 Grain oblong, loosely included, but not adherent. AVhen soaked 

 in water the ovary swells and the seed escapes, much as in 

 Sporobolus. 



Tufted perennials, usually low with spreading bases. Spikelike 

 panicle ovoid or usually oblong or cylindrical. 



There are 7-8 species found in the vicinity of the Mediterranean 

 Sea and in Central Asia. 



Kunth referred them to a section of Crypsis, but the resem- 

 blance is superficial. The axis of inflorescence in Cry2)sis is a flat 

 disk; in Heleochloa it is a more or less elongated rachis. In Cryp- 

 sis the empty glumes are above the articulation and fall off witli tlie 

 spikelet, and the glumes are quite those of Oryzete without any two- 

 nerved palea; in Heleochloa the empty glumes persist below the 

 articulation, and the glumes and palea are entirely those of Phleoi- 

 dese. Beauvoisgave the same name Heleochloa to a supposed genus, 

 apparently made up of a Sporoholus and a Fhleum. 



a. Spikes mostly exserted 1 



b. Spikes with bases included 2 



