Jennings: Contribution to Botany of Isle of Pines. 55 



rosette of soft leaves; blades 

 ciliate; spikelets 1.5-2 mm. long, 

 glabrous. 



III. Panicutn polycaulon. 

 Autumnal state erect or spreading. 

 Sheath velvety or pilose. 

 106. Panicutn chrysopsidi folium. 

 Sheaths not velvety or pilose. 

 Blades long and narrow; 

 spikelets papillose. 

 108. Panicutn fusif or me. 

 Blades not elongated; spike- 

 lets not papillose. 

 115. Panicum alhomarginatum. 

 Plants not forming winter-rosettes. 



Panicles narrow and compact with 

 appressed branches. 



113. Panicutn stenodes. 

 Panicles open usually diffusely spread- 

 ing. 

 Spikelets 1.5 mm. long, short- 

 pedicelled. 



107. Panicum exiguifloriim. 

 Spikelets on more or less elongated 

 pedicels. 

 Sheaths glabrous. 



105. Panicum diffusum. 

 Sheaths hispid. 



104. Panicutn cayennense. 

 One or both glumes awned or cuspidate. 



Fruit cuspidate, palea free at the tip; second glume 

 and sterile lemma tapering into a cuspidate 

 point or awn (Echinochloa). 

 Spikelets pointed, not awned. 



99. Echinochloa colonum. 



Spikelets awned 100. Echinochloa Crusgalli. 



Fruit not cuspidate, palea not free; awns arising 

 from a toothed summit. . 1 16. Oplismenus hirtelliis. 



Series II. Poaceae. 



Spikelets one to many-flowered, the imperfect or rudimentary floret, if any, 

 uppermost; rachilla articulated (except in Achlcena and Reynaudia) above the 

 glumes, which are persistent on the pedicel or rachis after the fall of the florets; 

 when 2- or many-flowered a manifest internode of the rachilla separating the 

 florets and articulated below them; spikelets laterally compressed. 

 Spikelets articulated below the glumes. 



Glumes tapering into awns; spikelets, including awns, over 3 cm. long. 



124. Achlcena piptostachya. 



