129a. Flowers in dense cottony heads; plants more or less white-woolly 79, in =COMPOSITAE=, p. 120.
129b. Pistillate flowers in an ovoid spiny involucre, ripening into a bur 3a, in =COMPOSITAE=, p. 114.
129c. Flowers minute, subtended by palmately cleft axillary bracts 1a, in =EUPHORBIACEAE=, p. 66.
129d. Plants without any of the preceding characters --130.
130a. Plants with milky or colored juice 10, in =EUPHORBIACEAE=, p. 67.
130b. Plants with tendrils, at least on the upper leaves 4a, in =LILIACEAE=, p. 11.
130c. Plants of nettle-like character, with stinging hairs 8b, in =URTICACEAE=, p. 24.
130d. Plants with sheathing stipules, surrounding the stem above the base of each leaf =POLYGONACEAE=, p. 25.
130e. Plants with smooth, pale, juicy, almost translucent stems 12a, in =URTICACEAE=, p. 24.
130f. Plants without any of the preceding structures or habits --131.
131a. Flowers axillary, solitary or in few-flowered cl.u.s.ters --132.
131b. Flowers in terminal, or terminal and axillary cl.u.s.ters --138.
132a. Leaves linear =CHENOPODIACEAE=, p. 28.
132b. Leaves of a broader shape than linear --133.
133a. Flower-cl.u.s.ters with bracts as long as or longer than the flowers --134.
133b. Flowers without conspicuous bracts --135.
134a. Leaves broadest below the middle 8a, in =URTICACEAE=, p. 24.
134b. Leaves broadest above the middle 2, in =AMARANTHACEAE=, p. 30.
135a. Princ.i.p.al leaves 3 cm. long or more --136.
135b. Princ.i.p.al leaves 2.5 cm. long or less --137.
136a. Flowers nodding in the axils of the leaves 1a, in =VIOLACEAE=, p. 75.
136b. Flowers erect in the axils 2a, in =ONAGRACEAE=, p. 78.
137a. Leaves narrowly oblong 1a, in =HALORAGIDACEAE=, p. 79.
137b. Leaves roundish and somewhat heart-shape 12a, in =SAXIFRAGACEAE=, p. 50.
138a. Flowers in racemes or simple spikes --139.
138b. Flowers in panicles or other branched cl.u.s.ters --141.
139a. Leaves toothed or lobed 52b, in =CRUCIFERAE=, p. 46.
139b. Leaves entire --140.
140a. Flowers sessile; leaves heart-shape =PIPERACEAE=, p. 19.
140b. Flowers pedicelled; leaves obovate 8b, in =PRIMULACEAE=, p. 87.
141a. Individual flowers distinct from each other, on pedicels --142.
141b. Individual flowers crowded in close cl.u.s.ters, or separate and sessile --143.
142a. Leaves finely serrate 3b, in =CRa.s.sULACEAE=, p. 49.
142b. Leaves entire 1b, in =CISTACEAE=, p. 74.
143a. Flower-cl.u.s.ters mingled with sharp-pointed bracts =AMARANTHACEAE=, p. 30.
143b. Flower-cl.u.s.ters without bracts, or (rarely) with bracts which are not sharp-pointed =CHENOPODIACEAE=, p. 28.
--144--
144a. Juice not milky --145.
144b. Juice milky; apparent flowers consisting of a few white or colored petal-like bracts, inclosing a few inconspicuous flowers without petals. In some of them a 3-lobed ovary with 3 styles may be plainly seen =EUPHORBIACEAE=, p. 66.
145a. Plants of the composite type, with several or many small flowerets closely aggregated into a dense head subtended by a calyx-like involucre of small bracts --146.
145b. Flowers solitary or in cl.u.s.ters, but not in involucred heads --147.
146a. Leaves compound with 3 leaflets; stipules present =LEGUMINOSAE=, p. 58.
146b. Stipules none =COMPOSITAE=, p. 113.
147a. Leaves compound or deeply lobed --148.
147b. Leaves simple and not deeply lobed --154.
148a. Flowers irregular =LEGUMINOSAE=, p. 58.
148b. Flowers regular --149.
149a. Petals 3 =LIMNANTHACEAE=, p. 68.
149b. Petals 4 --150.
149c. Petals 5 or more --151.