CLASB III. ORDER II.J GRASSES. 63 



he gi'asses of more importance than any other tribe of the vegetable 

 kingdom, both in an agricultural and commercial point of view. 



Grasses, particularly by the young student of Botany, are usually 

 ranked amongst the most difficult divisions of the Flora, and the col- 

 Isction and study of them are mostly deferred, or entirely neglected ; 

 lut the parts by which they are characterised, though small, are, after 

 a 'little practice, easily distinguished, and as readily and unerringly 

 referred to their proper genus and species as any other tribe of plants. 

 Indeed, no sooner does a person begin to take an interest in the inves- 

 tigation of this interesting tribe, than " the flower of the grass," to 

 adopt a beautiful Scripture expression, will be found to possess peculiar 

 attractions — " the grace of the fashion of it," becoming strikingly appa- 

 rent, as the examination proceeds. Grasses differ widely, however, 

 from other flowering plants, both in habit and structure (especially of 

 the flower), which may render it desirable that some explanation of 

 them should be given in this place. 

 The roots do not differ in any thing remarkable from those of other 



plants ; they are fibrous, tufted, or widely spreading. 

 The stems are subterraneous and superterraneous, and are inter- 

 cepted at various intervals by joiiits, which are formed by the 

 interlacement of the fibres, and constitute an impervious dia- 

 phragm or solid knot (nodus). The subterranean stems, or rhi- 

 zoma, are solid throughout, and the joints much closer together 

 than in the upper part of the stem; from those joints, which lie 

 mostly beneath the surface of the ground, roots are put out; and 

 some species are remarkable from the number of underground or 

 creeping stems (soboles) which they put forth ; these creep hori- 

 zontally below the surface of the ground, emitting at various in- 

 tervals roots, leaves, and flowering stems from their joints. The 

 superterranean stems, or culms, are cylindrical or fistular, but, 

 when first developed, solid, like the rhizoma from whence they 

 spring; but as their growth is much more rapid, they become 

 hollow, and the joints further separated from each other. From 

 each of these joints the leaves spring alternately, and envelope the 

 culms by a sheath-Yike expansion at their base, which is slit open 

 on one side; and frequently at the termination of the sheath, where 

 it expands into the blade, there is a peculiar thin membranous 

 or hairy process called a ligula. 

 The inflorescence is in the form either of a spike, a raceme, or pajii- 

 cle ; each division of which is called a spikelet (spictda), or lo- 

 custa. 

 The spikelets may be either one, two, or more flowered; sessile, or 



supported on a peduncle. 

 The flowers are mostly hermaphrodite (stamens and pistils in the 

 same flower); sometimes monoecious (stamens and pistils in sepa- 

 rate flowers on the same plant) ; or polygamous (stamens and pis- 

 tils united in some flowers, separate in others, either on the same 



