]2 BRITISH GRASSES. 



brace the stem, opening on one side, and are provided 

 with a scale or ligule ; they have the same varieties of 

 surface as the leaves of which they form a part, and are 

 narrow or inflated according as they fit tightly to the 

 stem, or encircle it in a loose and swollen manner. 



The ligule is a small membranous scale-like process, 

 attached to the inner side of the leaf and having its 

 origin at the top of the sheath, just where the leaf di- 

 verges from the stem. It is entire or bifid (cut into two 

 teeth), or torn at the margin, or fringed, or truncated 

 (when cut straight at the top), pointed when the apex is 

 abrupt, acuminate when it tapers, and decurrent when 

 running down the side of the sheath so as to be hardly 

 visible. 



The position of the leaf with regard to the stem is 

 oblique when it ascends from the sheath, but diverges 

 from the perpendicular ; perpendicular when it holds 

 itself quite upright ; horizontal when it stands at right 

 angles with the stem ; and bending when it arches from 

 the ligule to the apex. The leaves on a stem are equal in 

 number to the joints of the stem, and the sheaths gene- 

 rally cover the joints, especially the lower ones. 



The inflorescence is arranged in a compact or diffuse 

 form, and is either a spike, raceme, or panicle according 

 as the rachis is simple, or endowed with simple branches, 

 or with compound ones. Its form is glomerate or round, 

 as in Sesleria ccerulea; verticillate, with branches arranged 

 in whorls, as Panicum verticillatum ; secund or one-rowed, 

 when all the florets are on one side, as in Nardus stricta ; 

 cylindrical, round, long, and equal, as in Phleum pra- 

 tense ; ventricose when the head is thicker in the middle 

 and tapering to each end, as in Alopecurus agrestis ; ef- 

 fuse when the branches of the rachis spread widely, as 



