30 POACEAE 
Leaves 2-ranked, their sheath-margins usually not united: stem mostly hollow: fruit 
a grain (caryopsis). Fam. 1. Poac EAE. 
Leaves Sane. their sheath-margins united: stem solid: 
fruit an achen Fam.2. CYPERACEAE. 
Faminty 1. POACEAE — Grass FAMILY! 
Herbs or rarely woody plants, with often hollow stems (culms) 
closed at the nodes, and 2-ranked parallel-veined leaves, these consisting of 
2 parts, a lower (the sheath), enveloping the culm, its margins s overlapping 
or sometimes grown together, an upper (the blade), usually flat, while be- 
tween the two on the inside, a membranaceous hyaline or hairy appen 
(the ligule). Flowers perfect (rarely unisexual), small, with no distinct 
erianth, arranged in spikelets consisting of a s ortened axis (rachilla) 
ma ra 
sented by 2 (rarely 3) small hyaline scales E epe a e base of 
the flower inside the lemma and palea. e a, pale d inclosed 
flower constitute the floret. The oe are ie cone ager Mem 
in an inflorescence at the ends of the main stems or nehes. The 
or e (the single seed and the adherent p E may be o as 
in wheat, r permanently inelosed in the lem palea as in the oat. 
Ll T i : is from the ees as in pte of Sporobolus and 
Eleusine. The stems of bamboos are woody as are also those of a few 
en such as Olyra and Lasiacis, ed to e tribes. The eulms 
are solid in our species of the tr ibes Tripsaceae and ro A The 
margins of the sheaths are grown together in species of Bromus, Festuca, 
Melica, Panicularia, and others. The parts of the spikelet may be modified 
in various ways. The first, and more rarely also the secon , glume may n 
wanting. The lemmas may contain no flower, or even no pa ea, or may 
reduced or rudimentary. The palea is rarely wanting in perfect florets as 
in species of Agrostis.—Comprises about 500 genera and 7,000 species very 
widely distributed in latitude, a and habitat. The so-called cereals 
are of great economic importane 
Spiele with 1 perfect terminal floret (disregarding those of the staminate and 
euter spikelets) and a sterile or staminate floret below, usually represented by 
terile lemma only, one glume sometimes, both glumes rarely, wanti ing: articu- 
lation below the spikelets either in the pedicel, in the rachis, or B. PR base 
of a cluster of spikelets, the spikelets falling entire, singly, in groups, or together 
with joints of the rachis: spikelets, or at least the fruits, aoe or jess dorsally 
e Ed (except in some genera of Nazieae). (SUBFAMILY PANICATAE.) 
Glumes indurate: fertile lemma and lea nn or lend eem eous, the sterile 
emma (when present) like the fertile n texture. 
Spikelets P Rs Pas RUE the Staminate “above, on the same in- 
florescence, separate inflor Tribe I. TRIPSACEAE. 
DDR ts perfect, st staminate a Bener Res some- 
present. 
Spikelets in Lae one sessile and perfect, 
the other pedicelled and Tana n 
nate or neutral (the pedicellate on 
times obsolete, or rarely both pedicellate) : 
mas hyaline. Tribe II. ANDROPOGONEAE. 
em 
1Contributed by Albert Spear Hitchcock. 
