xxvii 



GROUP 3, MONOCOTYLEDONES 



la. Twining plants, with flowers in panicles or racemes 



DIOSCOREACEAE, p. 14, 



Ib. Plants with milky juice 13a, in COMPOSITAE, p. 115. 



Ic. Plants not twining (some climb by tendrils) and not with milky 

 juice 2. 



2a. Flowers in close spikes or heads, surrounded or subtended 

 by a green or colored bract, the whole resembling a single 

 flower; petals minute or wanting; leaves broad, not grass-like, 

 linear, or sword-shape ARACEAE, p. 8. 



2b. Plants with narrow, linear, grass-like, or sword-shape leaves 

 1 (a few species of Carex have broader, lanceolate to ovate 



leaves) ; flowers greenish, yellowish, or brownish, never brightly 

 colored, and frequently dry or chaffy in texture; perianth small 

 or wanting; individual flowers inconspicuous in size, but some- 

 times grouped into conspicuous clusters 3. 



2c. Plants with leaves of various widths, but the flowers petaloid, 

 i. e., with a white or colored, more or less conspicuous perianth, 

 and never chaffy in texture. In a few cases the flowers are 

 greenish, but the size and conspicuousness of the perianth ident- 

 ifies them in this class 9. 



3a. Flowers in the axils of dry, membranous or chaffy scales, which 

 are regularly arranged into spikes or spikelets of uniform size 

 and structure, which are variously grouped or clustered; fruit 

 an achene; grasses and sedges, with joined stems and sheath- 

 ing leaves, or leafless and the stems not jointed 4. 



3b. Flowers not subtended individually by dry, membranous, or chaffy 

 scales, and otherwise not agreeing with 3a 5. 



4a. Leaf-sheaths split on the side opposite the leaf; leaves 

 usually 2-ranked, i. e., in 2 longitudinal rows with the third leaf 

 above the first; stems rounded or flat, never triangular, usually 

 hollow GRAMINEAE, p. 4. 



4b. Leaf-sheaths closed into a continuous tube; leaves usually 

 3-ranked; stems frequently triangular, usually solid 



CTPERACEAE, p. 7. 

 5a. Flowers in dense spikes 6. 

 5b. Flowers in heads, racemes, or panicles 7. 



6a. Spike terminal, with pistillate flowers at the base and stam- 



inate ones at the apex TYPHACEAE, p. 2. 



6b. Spike short, apparently lateral, near the apex of the stem 



3a, in ARACEAE, p. 8. 



