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GRASSES OF SCOTLAND. 123 



very thin, and delicately fringed at the margins. Awn arising from 

 a little above the centre of the outer palea, sometimes from the cen- 

 tre, (liable to vary even in the same plants), rough ; twisted at the 

 base ; longer than the palea ; becoming bent when dry. 



longifolium, a variety with long linear flat leaves, the 



upper leaf very rough on both surfaces and margins, but rather more 

 so on the inner surface ; the second leaf rather broader and more 

 than three times the length of the upper leaf, very rough on the in- 

 ner surface, but nearly smooth behind ; most of the radical leaves as 

 long as the culm, narrower than those of the stem, perfectly smooth 

 behind, and very rough within ; all the leaves have a glaucous appear- 

 ance, especially on the inner surface. The stem roughish from above 

 downwards ; sheaths flattish, slightly carinated, strongly ribbed ; 

 roughish to the touch from below upwards ; root with several long 

 downy fibres; in other respects similar to Trisetum pratense. (Plate 

 LII.) This variety is found in moist shady woods near the sea in the 

 neighbourhood of Edinburgh. 



latifolium, a tall, stout variety, growing to the height of 



two feet or more ; the leaves short and broad, coming suddenly to a 

 point; the upper leaf flat, rough on the inner surface and edges, 

 nearly smooth behind, with a long, compressed, carinated sheath, 

 rough from below upwards ; the lower leaves folded, rough on the 

 inner surface, and perfectly smooth behind ; stem smooth ; root fibrous 

 (Plate LIII.) In other respects it agrees with Trisetum pratense. This 

 description and accompanying figure were taken from an authentic spe- 

 cimen gathered in the Isle of Arran, and which is now growing in the 

 Edinburgh Botanic Garden. It seems to be the Avena planiculmis of 

 Hooker, and answers to Smith's description of Avena alpina ; but as 

 to whether it be known to continental authors under those names ap- 

 pears doubtful. 1 cannot, however, discover any character sufficient- 

 ly prominent to consider it as any thing more than a variety of Trise- 

 tum pratense. The length and width of the leaves are liable to vary 

 according to the soil and situation, and the carinated sheaths cannot 

 be depended on as a character, as we frequently meet with it both in 

 the broad and narrow-leaved varieties. 



Obs. — Trisetum pratense differs from Trisetum pubescens in the 

 spikelets being larger ; large glume of the calyx more lanceolate ; ra- 



