6o 



GRASSES OF SCOTLAND, 



northern parts of North America. Its limit of altitude seems to be 

 about 1500 feet above the sea. 



Flowers in the third week of June, and ripens its seeds about the 

 end of July. 



The observations of Mr Lawson in his valuable work on agricul- 

 ture tends in a great measure to prove that the bulbous variety de- 

 serves a claim as a distinct species. He states, " that the seeds of the 

 true fibrous variety never produce bulbous-rooted plants, although 

 sown in the most light dry soils, and suffered to grow on such for a 

 great length of time. Seeds of the bulbous-rooted sort will, on the 

 other hand, produce plants having bulbous roots the first season of 

 their growth, on whatever kind of soil they may be sown." Such also 

 seems to be the opinion of Professor Lindley, Professor Schrader, Sir 

 Thomas Cullum, and others ; which Sir James Smith, Sir William 

 Hooker, and Professor Koch do not seem inclined to admit, as the 

 roots of Phleum pratense and Alopecurus geniculatus, which are mostly 

 fibrous, become bulbous on a dry barren soil. 



41. AVENA STRIGOSA. * 



Bristle-pointed Oat. 



Specific Characters. — Florets equal in length to the calyx, and 

 terminating in two long straight bristles. (Plate XXVI.) 



Description. — It grows to the height of three feet. The root is 

 annual, fibrous. Stem erect, round, smooth, and polished, bearing 

 four or five leaves, with smooth, striated sheaths ; the upper sheath 

 longer than its leaf, crowned with an oblong membranous, often rag- 

 ged ligule. Joints smooth. Leaves rather broad, acute, rough to 

 the touch on both surfaces, more or less glaucous ; the central rib 

 on the under surface polished. Infiorescence simple panicled, very 

 much resembling the common cultivated oat in appearance. Panicle 

 mostly turned to one side, with long, rough, lateral branches ; the 

 rachis mostly smooth. Spikelets large, oval, of two awned florets. 

 Calyx of two rather unequal acute membranous smooth somewhat 

 polished glumes (Fig 1) ; the lower glume the smaller, seven -ribbed ; 



" Avena strigosa, Linn., Smith, Koch, Hooker, Lindley. 



