42a. Leaves numerous and close, concealing the stem 2a, in =CISTACEAE=, p. 74.

42b. Leaves spreading, not concealing the stem --43.

43a. Leaf-scales in small cl.u.s.ters; flowers greenish, with 6 petals 2a, in =LILIACEAE=, p. 10.

43b. Leaf-scales distinctly opposite; petals 5, yellow 7a, in =HYPERICACEAE=, p. 74.

44a. Sepals 2 3, in =PORTULACACEAE=, p. 34.

44b. Sepals 4 or 5 =CRa.s.sULACEAE=, p. 48.

45a. Leaves pitcher-shape, open at the top =SARRACENIACEAE=, p. 48.

45b. Leaves tubular, closed at the end 37b, in =LILIACEAE=, p. 13.

GROUP 3, MONOCOTYLEDONES

1a. Twining plants, with flowers in panicles or racemes

=DIOSCOREACEAE=, p. 14.

1b. Plants with milky juice

13a, in =COMPOSITAE=, p. 115.

1c. 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 gra.s.s-like, linear, or sword-shape =ARACEAE=, p. 8.

2b. Plants with narrow, linear, gra.s.s-like, or sword-shape leaves (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 sometimes grouped into conspicuous cl.u.s.ters --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 identifies them in this cla.s.s --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 cl.u.s.tered; fruit an achene; gra.s.ses and sedges, with joined stems and sheathing 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 =CYPERACEAE=, 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 staminate ones at the apex =TYPHACEAE=, p. 2.

6b. Spike short, apparently lateral, near the apex of the stem 3a, in =ARACEAE=, p. 8.

7a. Flowers in globose heads which are arranged in spikes, the lowest heads pistillate, the upper staminate; ovary 1-celled =SPARGANIACEAE=, p. 2.

7b. Flowers in globose woolly heads terminating leafless unbranched stalks =ERIOCAULACEAE=, p. 9.

7c. Flowers in a spike-like raceme; ovaries 3-6, separate or nearly so =JUNCAGINACEAE=, p. 3.

7d. Flowers in heads or panicles, all perfect, not woolly, with one ovary --8.

8a. Leaves less than 1 cm. wide, or none; divisions of the perianth 6 =JUNCACEAE=, p. 10.

8b. Leaves 2 cm. wide or more; petals 5 2a, in =UMBELLIFERAE=, p. 80.

9a. Flowers regular, with all the petals of approximately the same size and shape --10.

9b. Flowers irregular, with the petals of each flower not of the same size or shape --22.

10a. Ovaries 3 or more, separate or barely united with each other at the base --11.

10b. Ovary one in each flower --12.

11a. Ovaries 3-6 in number; flowers in spikes or racemes; leaves linear =JUNCAGINACEAE=, p. 3.

11b. Ovaries more than 6 =ALISMACEAE=, p. 3.

12a. Flowers or flower-cl.u.s.ters lateral, axillary or apparently so --13.

12b. Flowers or flower-cl.u.s.ters terminal or on leafless stalks --14.

13a. Leaves minute and scale-like; flowers greenish-yellow 2a, in =LILIACEAE=, p. 10.

13b. Leaves linear, gra.s.s-like 3b, in =IRIDACEAE=, p. 13.

13c. Leaves lanceolate or broader, not gra.s.s-like or scale-like 2b, in =LILIACEAE=, p. 10.

14a. Divisions of the perianth 5-12 cm. long --15.

14b. Divisions of the perianth less than 5 cm. long --16.

15a. Flowers blue, or blue marked with yellow 1a, in =IRIDACEAE=, p. 15.

15b. Flowers not blue 12a, in =LILIACEAE=, p. 11.

16a. Flowers solitary --17.

16b. Flowers 2 or more, in some kind of a cl.u.s.ter --18.

17a. Leaves 2, broadly heart-shape, basal, on long stalks 1b, in =ARISTOLOCHIACEAE=, p. 25.

17b. Leaves not heart-shape 20, 20, in =LILIACEAE=, p. 12.