78 CLASSIFICATIOxV ACCOKDING 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. hete.rophylla 

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



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

 tissue between; each furrow with motor-cells, and 

 each vasctdar bundle joined to epidermis above 

 and below by a sclerenchyma girder. 



Bracliypodium pinnatum. Smooth. Ridges rounded. 



Hairs rare. The strong sclerenchyma girders below almost 



continuous laterally. Epidermal cells with sinuous thick 



w^alls, and a few tooth-hairs. 



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

 Melica nutans, M. unijiora, and Calamagrostis Epigeios also 

 come here. 



® Motor-cells confined to the innermost 2 — 4= furrows. 

 Sclerenchyma in a continuous band just in&ide the 

 thick cuticle belou: 



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 canescens and Spartina stncta also come here. 



