GRAMINEiE. 445 



with a pair of empty glumes (without paleas) at the base 

 and possibly a sterile one at the top, forming a spikelet. 

 These spikelets arranged in open panicles, bunches 

 spikes, or pairs (one of a pair stalked, the other sessile) ; 

 such spikes or pairs being again arranged in various ways. 

 Fruit 3. grain (one seed enclosed in and inseparable from 

 the wail of the ovary), usually enclosed between the now 

 hardened glume and its paleas. Endosperm mealy. 



A very large family with about 310 genera and 3,500 species, 

 found in all parts of the world, and often covering large areas. 

 Economically it is perhaps the most valuable to man of all 

 families, the leaves forming the staple food of cattle and horses, 

 the grains of man. 



From the cyperace^ the round stem, two ranked leaves and split 

 sheath easily distinguish this family. 



The glumes are referred to by their position as numbered in order from 

 the base of the spikelet. Thus glumes i and ii are the two sterile glumes ; 

 gl. i being always on the outer side of the spikelet, gl. ii on the inner 

 side, next the axis which bears it. Glumes iii, iv, v, etc., are the flowering 

 glumes, iii being vertically above i, iv above ii, v above iii and so on. 

 One or more of the glumes may have as a prolongation of its tip, or attached 

 to the back, a slender spine (awn), which is often bent and by its 

 hydroscopic twistings buries the grain (enclosed in the glume) in the soii 

 or the coat of some passing animal (cf. lierons-bill, p. ;3). The stalk of 

 the spikelet itself, on which the glumes are set is called the rachHla. 



ANALYSIS OF THE GENERA. 

 ' Spikelets jointed to their stalks, so that the two lowest 

 glumes come away with the grain (never more than one). 

 Flowers one or two, but if two the top one alone fertile. 

 See also j, calamagrostis. . A. FANICACE^, b 

 Spikelets not jointed to their stalks, so that the two lowest 

 glumes remain attached to it, while the rachilla breaks 

 between the glumes above. Flowers one, two or more. 

 See also e, isachne , B. POACE^, h 



a^ 



A. PANICACE^. 



Glume iii in fruit equal to i and ii in hardness, though 

 often much larger. . . . (panice^) . . . . c 

 Glume iii, and iv if it occurs, hyaline, so that the spikelet 

 b \ may appear to have only two glumes and one or more 

 paleas. Spikelets always in sets of two, unequally stalked, 

 or at the top of the spike a set of three. . . (andro- 

 POGONE.E) g 



