R. hederaceus: plant floating or spreading on mud; leaves roundish, ivy-like, with 3-5 broad, shallow lobes; flowers very small, white; carpels and receptacle glabrous. - Shallow water and mud. Fl. July, August.
** Flowers yellow; (terrestrial plants). † Leaves simple or undivided.
R. Lingua: stem erect, hollow, 2-3 feet high; leaves long, lanceolate, smooth, entire, or with only a few small teeth at the edge; flowers in a loose panicle, large, the petals bright shining yellow; carpels with a short, broad, flat beak. - Great Spearwort. - Marshes and ditches. Fl. July.
R. Flammula: stems more or less reclining at the base, 1-1 1/2 foot high, with a few loose branches; lowest leaves ovate, the remainder lanceolate or linear, nearly entire; flowers yellow, on long peduncles, seldom more than half an inch in diameter, often much smaller; carpels with a very short, usually hooked beak. - Spearwort. Marshes and wet pastures. Fl. June to August.
Var reptans: stems slender, creeping; flowers much smaller.
†† Leaves deeply cut. ‡ Carpels smooth, that is, having an even surface. § Leaves smooth, not hairy.
R. sceleratus: annual, erect, branched, about one foot high, glabrous, the stem hollow; lower leaves stalked, three-parted with obtusely-lobed segments, the upper sessile, trifid with narrow segments; flowers small, numerous, pale yellow; carpels very small and numerous, in a dense oblong head. - Wet places, sides of pools, etc. Fl. July to September.
§§ Leaves hairy.
R. acris: stems erect, six inches to 2-3 feet high, hairy; leaves stalked, palmately three-parted, the segments again cut into three acutely-toothed lobes, those of the upper ones narrower and fewer; flowers rather large, bright yellow, forming large loose panicles, the calyx lobes spreading horizontally; carpels ovate, glabrous. - Buttercups. - Meadows and pastures. Fl. June, July.
R. repens: distinguished by having creeping runners, and spreading calyx-lobes; and
R. bulbosus: known by the bulbous base of its stem, and by its reflexed calyx-lobes - both noticed at p. 43 - are also met with in flower during summer.
‡‡ Carpels slightly tuberculate near the edge.
R. Philonotis (hirsutus): annual, erect, much branched from the base, 1/2-1 foot high, hairy; leaves ternate, with stalked trifid leaflets; flowers numerous, rather small, pale yellow, the calyx-lobes reflexed; carpels marked with minute tubercles within the margin. - Moist fields and waste places. Fl. July to October.
‡‡‡Carpels covered with prickles.
R. arvensis: annual, erect, branching, nearly glabrous, pale green, 1/2-1 1/2 feet high; leaves once or twice deeply three-cleft, with narrow segments; flowers small, pale yellow; carpels few, rather large, much flattened, covered on both sides with conical prickles. - Cornfields; a troublesome weed. Fl. June. [See also p. 43.]