106 CLASSIFICATION ACCORDING TO [CH. 



* Upper flower perfect, lower staminate only. Tall oat- 

 like meadow-grass, with a bent and twisted dorsal awn 

 to the outer palea of the lower flower : silky hairs at 

 the base of palese. 



Arrhenatherum avenaceum, Beauv. 



The grasses most like this are species of Avena and Aira, 

 The former have two or more perfect flowers, and the only 

 broad-leafed Aira — A. ccespitosa, see p. 117 — is easily distinguished 

 by its leaves and its very small spikelets and short simple awns. 



** Upper flower staminate: lower perfect. Small hairy 

 grasses, with red-veined basal leaf-sheaths and short 

 simple awns. 



Holcus. 



t Erect, evenly hairy, glumes blunt, awn not pro- 

 truding. Common. 



H. lanatus, L. 



+t More or less procumbent, hairs chiefly at the nodes. 

 Glumes pointed. Awns simple and exserted. Rarer. 



H. mollis, L. 



B. Each spikelet with at least two perfect flowers, 

 often more. 



(1) Inflorescence spikate, the main axis bearing sessile 

 or sub-sessile spikelets, each, containing three or 

 more flowers. 



(a) Spike simple', axis stout and notched, each 



notch having one spikelet closely sessile in it. 



(i) Spikelets distichous, the flat side of each — i.e. the 

 edges of the glumes — being next the axis (rachis). 



Agropyrum. 

 * A weed with creeping stolons, and no awns 

 or mere points to the glumes. 



A. repens, Beauv. 

 1 See note, p. 87. 



