78 CLASSIFICATION ACCORDING TO [CH. 



Each vascular bundle has a sheath, but is isolated. 



Sclerenchyma at tips of the ridges dense : smaller bands 



below : strong at margins. Lower cuticle strong. Leaf 



rolls up. 



The flat upper leaves oiFestuca rubra (Fig. 20) and F. heterophylla, 

 are somewhat similar in type. They have stiflf hairs on the ridges. 



= = Ridges not more than 2 — 3 times as high as the 

 tissue between; each furrow with motor-cells, and 

 each vasmdar bundle joined to epidermis above 

 and below by a sclerenchyma girder. 



Brachypodium pinnatum. Smooth. Ridges rounded. 



Hairs rare. The strong sclerenchyma girders below almost 



continuous laterally. Epidermal cells with sinuous thick 



walls, and a few tooth-hairs. 



Note the differences from B. sylvaticum, p. 76. 

 Melica nutans, M. uniflora, and Calamagrostis Epigeios also 

 come here. 



© Motor-cells confined to the innermost 2 — i: furrows. 

 Sclerenchyma in a continuous band just inside the 

 thick cuticle below. 



Festuca duriuscula. The ridges are only about half 



to one-third as high again as the thickness between, and 



the motor-cells in four series at the base of the three 



innermost ridges. Each ridge has only one isolated 



sheathed bundle, without girders. Stomata on the flanks 



of the ridges, and few in number. The sclerenchyma forms 



a thick band just inside the strong cuticle below. The leaf 



is conduplicate, not convolute. 



This applies particularly to the more open leaves : the subulate 

 leaves belong to the next type (see Fig. 27). 



Aira caneseens and Spartina striata also come here. 



