ch. vn] Botanical Description of Species 



105 



IV 



Stems somewhat creeping and rooting at the nodes. Young shoots 

 compressed and with prominent keels. Sheaths entire, glabrous 

 but rough, of a spongy texture owing to air-cavities within. Blades 

 often an inch or more in width, folded in shoot, broadest near 

 base, tapering very gradually to an acute apex ; smooth or rough, 

 ribless above, and keeled on the lower surface. Yellowish triangles 

 at base. Ligule membranous, and usually short. No auricles. 

 Frequent in Britain. 



Flowers about July; culms varying from 3 to 

 6 feet high. Panicle erect, spreading, large and 

 graceful. Spikelets numerous, ovate, 4-10 flowered. 

 Glumes unequal, blunt, and without lateral nerves. 

 Flower without a " web " at its base. 



"Seeds." Outer palea 3-4 mm. long, rounded 

 off at apex, awnless, and seven-nerved, the dorsal 

 nerve minutely toothed. Rachilla cylindrical and 

 outstanding. The "seed" is entirely free from hairs 

 and is of a golden-brown colour. (Fig. 111.) 



Glyceria fluitans, Sm. (Floating Sweet-grass.) 

 (Fig. 110.) 



A perennial and somewhat creeping semi-aquatic 

 species closely allied to the last, but capable of 

 growing in drier situations. Young shoots flattened ; 

 sheaths entire, keeled, striated, with large air-cavities. 

 Blade soft, thin, broad and blunt, with numerous 

 low flat ribs above, and a very fine keel below 

 extending to the apex. At the base of the blade 

 are two conspicuous yellow areas of a triangular 

 shape. Ligule prominent, membranous, acute or 

 rounded off. Auricles absent. Frequent in Britain. 



Flowers late in June; culms 18 to 24 inches high. Inflores- 

 cence a simple panicle or even nearly spikate; lax, slender, and 

 frequently a foot or more in length. The branches are very 

 widely spread apart during flowering, but are close to the main 

 axis before and afterwards. Spikelets few, long, narrow, con- 

 taining from six to nearly twenty flowers. Glumes very unequal, 

 the upper one the larger ; both membranous and without lateral 

 nerves. Palese without a "web" at their base. 



Fig. 109. 



"Seed" of 

 Festuca, sylva- 

 tica. x 10. Note 

 the very pro- 

 minent mar- 

 ginal ribs (r) 

 of the inner 



