SPERMATOPHYTA. 



CHARLES F. MILLSPAUGH AND AGNES CHASE. 



Herbaceous or rarely woody plants. Flowers without a distinct 

 perianth, perfect or unisexual, solitary or several together in spike- 

 lets, which are arranged in spikes, racemes or panicles, and which 

 consist of a shortened axis (rachilla) and 2 or more chaff-like, dis- 

 tichous, imbricated bracts (glumes], of which the first 2 (rarely i, or 

 more than 2) are empty (empty glumes] ; in the axil of each of the suc- 

 ceeding bracts (floral glumes] is, normally, borne a flower; flower 

 sometimes wanting, the glume then being termed a sterile glume 

 ("flos neuter " of the older authors). Opposed to each floral glume, 

 with its dorsum toward the rachilla, is a 2-nerved bract (palea), these 

 together forming the fruiting glumes, which in the Panicece and some 

 others form an indehiscent covering about the enclosed free grain 

 (true seed), a caryopsis rich in albumen. Stamens usually 3 (6 in 

 GUADUA), with slender filaments and 2-celled versatile anthers; pistil 

 with a i-celled, i-ovuled ovary, with 2, usually plumose, stigmas. 



Rachilla articulated below the empty glumes, spikelets falling from the 

 pedicel entire or together with certain joints of the rachis at 

 maturity. Spikelets i-flowered (or rarely a lower imperfect 

 flower): 



Fruiting glumes hyaline, empty glumes indurated, spikelets in 

 racemes or spikes whose articulate axes break up at maturity: 

 Spikelets monoecious, pistillate spikelets en- \ 



closed in a bony involucre below the stami- C Coix. 

 nate panicle ) 



Spikelets heterogamous, or all perfect, in pairs at the joints of the 



rachis, i sessile, i pedicellate: 

 Joints of the rachis greatly thickened and ex- \ 



cavated for the reception of the perfect [ Hackelochloa. 

 spikelets ) 



Joints of the rachis not thickened nor excavated: 



Spikelets all perfect Saccharum. 



Spikelets heterogamous: 



Grain elongated, terete Andropogon. 



Grain oval, dorsally compressed Sorghum. 



Fruiting glumes membranaceous, spikelets in -> 



groups surrounded by a pseudo-involucre / //,,/;./,/;. 

 formed by the connate indurated fimC/**""**"* 

 glumes of each, falling off entire 



*The cuts present a portion of the inflorescence (spike, raceme or panicle) or a single spike- 

 let magnified 5 diameters (except where noted natural size in Coix and OLYRA); the fruiting glumes 

 and grain magnified 10 diameters, and a transverse section of the latter at its greatest diameter, the 

 base of the section being the ventral side/, e., the side bearing the hilum. 



IS 



