ANTHOPHYTA 359 



Family 31. Poaceae. Grasses, with 2-ranked leaves. 



(Sp. about 3,545.) 



There are six tribes and several sub-tribes, of which the 

 Bamboos are the lowest, while the 

 Agrostideae, Paniceae and Maydeae 

 are at the summits of as many di- 

 verging phyletic lines. These groups 

 may be distinguished as follows: 



A. Woody plants; a joint between the leaf-blade and the 



sheath. 1. Bamboos. (Bambuseae) 

 Bambusa. 



B. Herbaceous plants; no joint between the leaf-blade 



and sheath. 



I. Spikelets with the larger flowers at the base. 



1. Spikelets typically containing several to many 



flowers. 



a. Mostly arranged in panicles; awns ter- 



minal. 2. Fescue Grasses (Festuceae) 

 Bromus. 



b. Arranged in panicles; awns dorsal. 2a. 



Cat Grasses (Aveneae) Avena. 



c. Sessile in two rows on the opposite 



sides of the main stem. 2b. Wheat 

 Grasses (Triticeae) Triticum. 



d. Sessile in two rows on one side of a flat- 



tened axis. 2c. Gramma Grasses. 

 (Chlorideae) Bouteloua. 



2. Spikelets containing but one flower. 3. Red- 



top Grasses (Agrostideae) Agrostis. 



II. Spikelets with the larger flowers at the top. 



1. A joint above the empty glumes. 



a. Spikelets with five glumes; palets one- 

 nerved. 4. Canary Grasses (Phal- 

 arideae) Phalaris. 



2. A joint below the empty glumes. 



a. Spikelets flattened laterally, one-flowered. 



4a. Rice Grasses (Oryzeae) Oryza. 



b. Spikelets not flattened laterally, one to 



two-flowered. 



(1) Stems hollow, medium sized to 

 small. 5. Panic Grasses (Paniceae) 

 Panicum. 



