NATURAL HISTORY. 6 



to express these, like the terms used in other departments of 

 natural history, are technical ; and hence, in detailing the 

 natural history of the grasses, the use of technical language to 

 a greater or less extent, cannot be avoided. I shall endeavor, 

 however, by the use of plates and sj^nonyms to bring the de- 

 scription of species within the easy comprehension of every one 

 "who will carefully examine the subject. 



The flowers of the grasses are arranged on the stem in spikes, 

 as where they are set on a common stalk without small stalks 

 or branches for each separate flower, as in Herds-grass, (^phlemn 

 pratense^^ or in panicles, or loose subdivided clusters, as in 

 orchaud grass, (dactylis glomerata.^ A panicle is said to be 

 loose or spreading, as in redtop, (^agrostis vulgaris,') when the 

 small branches on which the flowers are set, are open, or ex- 

 tended out freely in different directions ; it is said to be dense, 

 or crowded or compressed, when the branches arc so short as to 

 give it more or less of the spike form. 



The spikelets (Fig. 2) have a calyx, (Fig. 4) containing one, 

 two or more florets, (Fig. 3.) This whole arrangement will 

 be seen in Fig. 1, which represents a stalk of the common 

 annual spear grass, (^poa annua,') a plant familiar to every one 

 as often troublesome in gravel walks and on hard, dry soils. 

 Here the joint, the stem or culm, clasped by the sheath of the 

 leaf, the leaf itself, the ligulc and the spikelets, all distinctly 

 appear, and the reader will do well to make himself familiar with 

 the few technical terms used by a study of this figure, in con- 

 nection witli Fig. 2, where the spikelet is so magnified as to show 

 the florets atid the calyx very distinctly, all of which are generally 

 very easily seen with the naked eye, and Fig. 3, showing a floret 

 still more magnified, with its two palea), the outer palea being 

 the longer and generally keeled, — that is, having one, three or 

 more longitudinal ribs, often having on the back, base or sum- 

 mit, an awn or beard of difl'erent lengths, as in the oat and 

 brome grasses, the inner palea with two separate fringed ribs, 

 each on a fold at the side. The calyx, bract or outer scale of 

 the spikelet, is shown very much magnified in Fig. 4, composed 

 of two glumes, the upper and lower, the upper glume being the 

 larger. One or both of the glumes are sometimes wanting. 



In Fig. 5, is shown the pistil magnified, consisting of the 

 nectary, composed of one or two fleshy scales, (in some plants 



