CLASS HI. ORDER 11.] GRASSES. 65 



cases, put out roots from their nodi or joints, each of wliich heconies a 

 distinct plant; so that, by means of these natural layers, the plants are 

 greatly increased, and the pasture in which they happen to grow mate- 

 rially improved. On the other hand, the leaves and young stems being 

 mostly preferred by grazing cattle, they are cropped close to the ground, 

 and would appear irrecoverably injured; but it commonly happens 

 that the more they are cropped, the more freely do they propagate 

 themselves by offsets from their roots ; this is a means of vast increase, 

 resulting in the formation of large tufts, a property which renders 

 many of the gi'asses so abundantly productive, and well suited for per- 

 manent pastures : it is by this means, that Wheat is often so produc- 

 tive; a single grain having been known to put up above an hundred 

 culms or stems, each bearing from fifty to a hundred grains — a most 

 astonishing increase ! Again : many of the alpine grasses, or those 

 growing on high exposed situations, where the heat of summer is not 

 sufficient to ripen the seeds, do not all flower, but are in some instances 

 viviparous ; and even those which do produce flowers, are frequently 

 found in that state. The roots of many species of grass are, when 

 gr'owing in a situation favoured with a plentiful supply of moisture, 

 simply fibrous ; but if the ground in which they vegetate becomes dry, 

 or the plants are removed to a less humid situation, they form bulbs or 

 tubers — a means admirably adapted by nature to lay in store a supply 

 of nourishment for the plant in times of drought. Some grasses grow 

 and flourish best in low swampy marshes, and even in water (but none 

 are marine) ; others on particular soils, as sand, chalk, clay, &c. ; or 

 they prefer lower or more elevated situations, — as, for instance, Poa 

 aquatica, Calamagrostis arundinacia, Alopeciirus gcniculatus, &c. are 

 found in low swampy or watery places ; while Feshica orina, Poa 

 alpina, Aira alpina, &c. occur on highlands or mountainous districts ; 

 and Ammophila arundinacea, Phleum arenarlum, Poa bulbosa, &c. 

 upon loose, sandy shores. 



It might, a priori, be supposed that a tribe of plants so extensive in 

 its characters, and distributed through every variety of climate, soil, 

 and situation, would present avast diversity in modification and habits; 

 such, in fact, is found to be the case. The grasses are solitary, or 

 social, multiplying and spreading to a great extent, erect or creeping, 

 simple or branched, of almost every variety of height, from a few inches 

 to upwards of two hundred feet, — assuming the port and character of 

 trees, with foliage equally various, and roots not less so. Some species, 

 from the fact of their producing large seeds containing a great portion 

 of farinaceous matter, have been called Cereal, or Co^-n-grasses ; and 

 others, producing smaller seeds, but as furnishing a nutritious herbage 

 for cattle, pas^ora/ ox fodder grasses. 



The whole order, comprehending about two thousand species, with 

 scarcely more than one exception, are wholesome ; abounding in nutri- 

 tious fcBculent matter, and sugar ; — indeed, the abundance of the latter 



VOL. I. K 



