[*][*] Achenes beset with rough points or small prickles; annuals.
R. muricàtus, L. Nearly glabrous; lower leaves roundish or reniform, 3-lobed, coarsely crenate; the upper 3-cleft, wedge-form at the base; petals longer than the calyx; carpels flat, spiny-tuberculate on the sides, strongly beaked, surrounded with a wide and sharp smooth margin.—Eastern Virginia and southward. (Nat. from Eu.)
R. parviflòrus, L. Hairy, slender and diffuse; lower leaves roundish-cordate, 3-cleft, coarsely toothed or cut; the upper 3–5-parted; petals not longer than the calyx; carpels minutely hispid and rough, beaked, narrowly margined.—Norfolk, Va., and southward. (Nat. from Eu.)
10. ISOPỲRUM, L.
Sepals 5, petal-like, deciduous. Petals 5, minute, wanting in the American species. Stamens 10–40. Pistils 3–6 or more, pointed with the styles. Pods ovate or oblong, 2–several-seeded.—Slender smooth perennial herbs, with 2–3-ternately compound leaves; the leaflets 2–3-lobed. Flowers axillary and terminal, white. (From ἰσόπυρον, the ancient name of a Fumaria.)
1. I. biternàtum, Torr. & Gray. Petals none; filaments white, club-shaped; pistils 3–6 (commonly 4), divaricate in fruit, 2–3-seeded; seeds smooth.—Moist shady places, Ohio to Minn. and southward. May.—Fibres of the root thickened here and there into little tubers. Aspect and size of the plant much as in Anemonella.
11. CÁLTHA, L. Marsh Marigold.
Sepals 5–9, petal-like. Petals none. Pistils 5–10, with scarcely any styles. Pods (follicles) compressed, spreading, many-seeded.—Glabrous perennials, with round and heart-shaped or kidney-form, large, undivided leaves. (An ancient Latin name for the common Marigold.)
1. C. palústris, L. Stem hollow, furrowed; leaves round or kidney-shaped, either crenate or dentate or nearly entire; sepals broadly oval (bright yellow).—Swamps and wet meadows, common northward. April, May.—Often called incorrectly Cowslips; used as a pot-herb in spring, when coming into flower. C. flabellifolia, Pursh, is a weak slender form, with open-reniform leaves and smaller flowers (1´ broad or less), occurring in cold mountain springs, N. Y. to Md. (Eu.)