To make the kej' as useful as possible to tlie reader, who 

 is not familiar with botanical terms, a glossary is added, and 

 the following elementary description of the structure of grasses 

 is given. (See also Figs. 1 and 2.) 



Fig. 1. — B. Festnca elatior. Spikelet witli two lower florpts openeil oul . 

 fi Lower ghime. h Upper giume. c Valve, d Pale. B. Festnca elatior. 

 Floret with Valve removed, a Pale, h Lodiciiles. c Stamen, cl Ovary with 

 two feathery styles. G. Eragrostis sujperha. Spikelet. a Lower gliune. h Upper 

 uiume. c Valve. Numerous florets in the spikelet far exsert?d from the 

 li'lumes. D. Achneria capensis. Spikelet. a Lower glume, i' Upiier glume, r 

 Valve of lower floret, d Pale of lower floret, e Valve of <ipper floret. /' Pale of 

 upper floret. Two florets enclosed in the glumes. E. Axonopus semiaiaAxin var. 

 ecldonii. Spikelet. a Lower glume, h Upper glume, c Valve of male floret, 

 (/ Valve of the perfect floret, e Pale. Only one perfect floret, with (me male 

 floret below it. F. Aristida hijyartita. Spikelet. a Lower glume. 6 Upper glume, 

 r Valve with 3 branched awn. Only a single floret in the spikelet. G. 

 Aiidropogon pertiisus. a Sessile floret with lower glume pitted. Awned. 

 i Pediceiled floret usually male. Awnless. (Figs A. and B. after Strasburger). 



