GRASSES OF SCOTLAND. 9l 



Jive-ribbed, all the ribs smooth, without hau-s, except the lower half of 

 the dorsal rib, which is furnished with a few delicate silky hairs 

 (Fig. 4). Inner palea rather shorter than the outer pale a, membra- 

 nous, with two green marginal ribs delicately fringed. Filaments 

 three, capillary. Anthers short, pendulous, notched at each end. 

 Styles two, distinct, short, naked. Stigmas prominent, feathery. 

 Ovarium ovate, glossy, somewhat wrinkled. Scales membranous, 

 broad, acute. (Fig. 5.) 



Obs. — This grass in its external aspect is very similar to some va- 

 rieties of Poa pratensis, but is readily distinguished in the Jioi-ets not 

 being webbed, and the outer palea with no hairs on the lateral ribs ; 

 — whereas in P. pratensis the lower florets are distinctly webbed, and 

 the marginal ribs of the outer palea are furnished with hairs. (See 

 Plate XXXI.) 



From Poa la.ra and Poa alpina in the branches of the panicle 

 being smooth, and the outer palea distinctly five-ribbed : — whereas in 

 P. laxa and P. alpina the branches are rough, and the outer palea 

 only three-ribbed. (See Plates XXX\TI. and XXX^TIL) 



serica, a common variety, with plain short leaves, Li- 



gule prominent, very thin and obtuse. Spikelets usually of three 

 florets. The two lateral ribs on each side of the outer palea covered with 

 white silky pubescence ; in other respects the same as P. annua. Fre- 

 quent on moist marshy soil. (Plate XLI.) 



Poa annua, one of the commonest of all our grasses, flowering 

 throughout the whole summer, growing on any kind of soil, in every si- 

 tuation from the low wet meadow to the dry mountain top, at an eleva- 

 tion of between 3000 and 4000 feet above the sea. It produces an 

 early herbage, which cattle are fond of, especially cows, but its beinw 

 an annual, and often destroyed by a continuance of dry weather, ren- 

 der it unprofitable to the farmer for cultivation. 



It is a common grass throughout Britain, also a native of Lapland, 

 Norway, Sweden, Denmark, Germany, France, Spain, Portuo-al, 

 Switzerland, Italy, Xorth Africa, North and South America, and 

 North Asia. 



