MONOCOTYLEDONOUS OR ENDOGENOUS PLANTS. 591 



spikelets, consisting of 2-rankecl imbricated bracts or scales, 

 of which the exterior or lower ones, subtending one or 

 more floAvers, are called glumes, and the two inner ones, 

 inclosing the 1-celled 1-ovuled ovary, and 1-11 (commonly 

 3) hypogynous stamens, are called palece ; perianth none, 

 or composed of 1-3 minute hypogynous scales (squamulce); 

 anthers Yersntiley 2-celled; styles 2-3, with hairy or plu- 

 mose stigmas; fruit a caryopsis (grain) ; embryo placed on 

 the outside and near the base of mealy albumen; root 

 fibrous. 



SYNOPSIS. 



Tribe I. Oryzese. Spikelets 1-flowered, mostly im- 

 perfect. Glumes none. Palece 2. Stamens 1-11. 



Flowers perfect, cnmpressed-panided- Palece, unequal, dilate Leersia. 



moncecious ; the pislUlate and Btammate ones in the same panicle . .Zizkhik. 



/ in sqmrate spikes. 



HYDKOCnLOA. 



dioecious, in terminal spikes Monanthochloe. 



Tribe II. Agrostideae. Spikelets 1-flowered, or 

 with the pedicel of a second flower above. Glumes 2. 

 PalecB mostly 2, the lower one often awned. Stamens 1-3. 

 Spikelets in open or closely spiked panicles. 



* Glumes united at the ba^e, strongly compressed-keeled. 



Lower palea awned on the back, the upper wanting. Flowers spiked. .Alopecuru?. 



*♦ Glumes distinct, concave oi' keeled ; palece. membranaceous ; grain free ; spikelets 

 in open w contracted panicles. 



Flowers awnless. Seed loose in the globose or obovoid pericarp SronoBOLUs. 



Pale(E shoi'ter than the nearly equal glumes, the lower awned on the back, the upper 



sometimes toanting Agrostis. 



Lower glume smaller than the upper one. Palece bearded at the base, th". lotver one 



mucronate or awn-pointed. Stamens 3 Muhlenbergia. 



*** Palece raised on a hairy stalk ; the lower one awned, indurated, and involute, 

 closely investing the grain. 



Lower palea with a single contorted aivn jointed with its apex. Panicle short. 



Stipa. 

 triple-aicned. Panicle elongated Aristida. 



