76 CLASSIFICATION ACCORDING TO [CH. 



Veins not more than 10 — 20 in each half 

 lamina. 



@ More or less conspicuorisly hairy. The smaller 

 bundles isolated and devoid of girders. 



Bromus sterilis. Girders to the stronger bundles only. 

 Stiff hairs above and below. Motor-cells poorly developed 

 between each pair of low ridges. No pronounced cuticle. 

 A faint sclerenchyma-band at margin, and at apex of low 

 rounded keel. Stomata on both faces. 



Bromus arvensis. Similar to B. sterilis, with stiff 

 hairs commoner below. Harsh in cutting. 



B. giganteus shows no hairs, but I cannot distinguish the Bromes 

 generally by the leaf anatomy. 



Anthoxanihum odoratum. No keel, ridges obsolete, 

 the stronger bundles only with girders. Motor-cells con- 

 spicuous between all the ribs. Marginal sclerenchyma, 

 and that above and below the bundles, poorly developed. 

 A few coarse hairs both above and below, and stomata on 

 both faces. Leaf thin and narrow. 



Hordeum murinum. Few girdered bundles, and 

 sclerenchyma at margins poor. Hairs sparse and coarse. 



Bromus asper, Brachypodium sylvaticum and Lagurus 



also come here. 



In all these grasses the epidermal cells are chiefly long, rect- 

 angular or slightly hexagonal, with thin and plane walls. 



© © Hairs none or very rare on the sections. 



Phleum pratense. Low rounded ribs with motor-cells 

 between. The larger vascular bundles girdered. Stomata 

 about equal on both faces. No hairs. No keel. Marginal 

 sclerenchyma scanty. 



