﻿GRASSES OF SCOTLAND. 51 



rough, throughout its whole length, protruding at all times conspicu- 

 ously beyond the calyx, when dry becoming bent but never curved ; 

 in other respects, the upper floret is similar to the lower one. 



Obs. biaristatus, (Plate XXII.) This variety, when 



compared with Holcus mollis, has larger and fewer spikelets, generally of 

 a bleached appearance ; the ligule longer ; the florets nearly of equal 

 size, as long as the small glume of the calyx ; acute at the summits, both 

 furnished with a long dorsal awn, rough throughout the whole length. 

 Root creeping. At first I was led to consider this grass as a distinct 

 species (in consequence of finding the awns constant in all those speci- 

 mens I examined), and stated it as such at a meeting of the Royal 

 Society of Edinburgh ; but having since had an opportunity of exa- 

 mining several dozen specimens from various localities, and not find- 

 ing the characters constant throughout all the florets of the same pani- 

 cle, I am induced to consider it as only a variety of //. mollis. In some 

 specimens the spikelets on the upper part of the panicle have both their 

 florets distinctly awned, while the florets of the lower spikelets are si- 

 milar in every respect to those of H. mollis. This variety is frequent- 

 ly met with in damp shady woods, and occasionally in open boggy si- 

 tuations. It flowers early in July. 



parviflorus, (Plate XXII.) a variety from nine to twelve 



inches high, with very small spikelets of the size represented in the fi- 

 gure, being not more than half the size of those of Holcus mollis. 

 Flowers early in July, and is found in dry sandy woods. 



Holcus mollis is distinguished from Holcus lanatus (two species very 

 closely allied), in the large glume of the calyx being acute ; the la- 

 teral rib situated nearer to the keel than to the inner margin. Awn of 

 the floret minutely toothed its whole length, (see Fig. 4) ; — whereas in 

 H. lanatus the large glume is more obtuse, tipped with a minute point 

 or awn ; lateral rib situated nearer the inner margin than to the keel ; 

 awn of the floret perfectly smooth nearly its whole length, and being 

 roughish only on the upper third. (See Fig. 4). 



This grass is considered by farmers as a most troublesome weed, 

 and with difficulty eradicated, especially when it gets possession of a 

 soil that is favourable to its growth. Its long creeping root, which 

 is said sometimes to exceed the length of four feet, is very impoverish- 



