GENERA. xix 



c. Spikelets all fertile, in a compound spike, tiled all round, and furnished with a bristle- 

 like involucrum. 



d. Spikelets in sets, all fertile, one sessile, and one or two stalked ; enveloped in long 

 silky hairs ! 



e. Spikelets all fertile, scattered, not enveloped in hairs, or sun'ounded by an involucruni. 



iii. Si)ikelets one- or more flowered, without additional exterior scales (which are likewise 

 wanting in the following sections), placed in two rows on one side of a flattened rachis. 



iv. Spikelets sessile, two- or more flowered, in a head or spike, tiled all round. 



V. Spikelets scattered, one- or more flowered. Elts. enveloped in silky hairs. 



vi. Spikelets scattered, one-flowered, without glumes ! 



vii. Spikelets scattered, in a spike-like panicle or head. Glumes one-flowered. 



viii. Spikelets scattered, in a loose panicle. Glumes one-flowered. 



ix. Spikelets scattered, in a loose panicle, with a second imperfect Fit. 



X. Spikelets scattered, with more than one perfect Fit. 



a. Glume nearly, or quite, equalling spikelet. 



b. Glume decidedly shorter than spikelet. 



E. In Hexandria Digynia. Oryza. 



r. In Moncecia Triandi'ia. Coix. Zea. The former is said to be naturalized near Paler- 

 mo, and the latter is extensively cultivated in s. Europe. 



i. Spikelets in opposite rows, on an alternately channeled rachis. 

 a. Spikelets with two or more flowers, all perfect. 



906. LOLIUM. Spikelets placed edgewise on the rachis ! Lower Glume very obscure or 

 wanting, p. 417. 



905. BBACHYPODIITM. Glumes unequal, ribbed, much smaller than the outer pale. 

 Spikelets on short stalks, more widely separated than is usual in Triticum. p. 417. 



907. TBITICUM. Glumes nearly equal, opposite, broad, embracing the solitary spikelet. 

 Pale terminating rather abruptly, and generally with a point or seta. p. 418. 



908. SECALE. Glumes narrow. Spikelets solitary. Pale gradually tapering into a long 

 seta. Seed crested, p. 419. 



909. .^GILOPS. Ghunes placed rather obliquely ; these and the outer pale herbaceo- 

 coriaceous, turgid, terminating in several stout setas. p. 419. 



910. ELYMUS. Spikelets 2 or 3 together. Glumes on one side. p. 419. 



885. GAITDIKTIA. Glumes unequal, much shorter than spikelet. Outer Pale with a 

 geniculate and twisted dorsal awn. Rachis brittle, p. 406. 



b. Spikelets all fertile, with only one perfect Fit., placed edgewise to the rachis, and when 

 closed imbedded in it, so as to form a continuous cylinder or prism. 



915. IiEPTITKUS. Glumes 1 or 2 on the same side of the unarmed spikelet, which 

 contains one perfect Fit. and an interior rudiment, p. 420. 



c. Spikelets in threes: the lateral usually barren, stalked; none with more than one 



perfect Tit. 



911. HORDEUM. Glumes setaceo-aristate, both on one side of the spikelet. A superior 

 Rudiment in each Spikelet towards the rachis. p. 420. 



Elymus europceus. Sclerochloa Triticum and divaricata. 



ii. Spikelets one-flowered, with additional scales ; the rudiments of one or more 



exterior Fits. 



[In Andropogon, Saccharum, Erianthus, and Imperata, from the delicacy of the parts, it is 



d 2 



