IX] "SEEDS" 139 



Digraphis differs in the stout caryopsis, smaller size, double hair- 

 tuft. Arundo has a long pointed palea and long silky basal hairs 

 and is larger. 



Psamma arenaria, Beauv. 



Palea 11 '5 mm. ovate-lanceolate, papery, 4 — 5 nerved, 



as rolled round the fruit about l'3mm. diameter, yellow, 



and with a small tuft of stiff fine hairs at the base. Mere 



trace of awn, sub-terminal. Fruit 4 — 5 mm. long, obovate, 



pale-brown. 



A shore-grass, not often seen as " seed " : more valuable as a 

 sand-binder than as fodder, though the young shoots are grazed. 



tt Palea acuminate, and only about 4: mm. long: 

 caryopsis 1 -4 mm. 



Digraphis arundinacea. 



A Fen-grass, but coarse and not in use except the young growth, 

 and for thatching. 



Digraphis arundinacea, Trin. 



Palese ovate-lanceolate, nerveless and awnless, but silky 

 with double basal hair-tuft, and polished at the base; 

 smooth, hard and shining, and closely investing the 

 caryopsis which has no groove. Dark grey in colour. The 

 glumes are without awns or wings, and are left behind. 



The allied Phalaris canarie?isis has wing-like keels to the glumes. 



Triodia also comes into this group, with short basal hairs ; but 

 its broad ciliate palea, 6 mm. long, has a short mucronate point 

 between two teeth (Fig. 40). 



(2) Hairs at the base forming a fluffy "web." 



PalecB thin, 2 — 3 mm. long. 



Poa pratensis. 

 P. trivialis. 

 P. compressa. 

 P. nemoralis. 



