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.) 12. TRÓLLIUS, L. GLOBE-FLOWER. Sepals 5--15, petal-like. Petals numerous, small, 1-lipped, the concavity near the base. Stamens and pistils numerous. Pods 9 or more, sessile, many-seeded.--Smooth perennials with palmately parted and cut leaves, like Ranunculus, and large solitary terminal flowers. (Name thought to be derived from the old German word _troll_, a globe, or something round.) 1. T. láxus, Salisb. (SPREADING GLOBE-FLOWER.) Leaves 5--7-parted; sepals 5--6, spreading; petals 15--25, inconspicuous, much shorter than the stamens.--Deep swamps, N. H. to Del. and Mich. May.--Flowers twice the size of the common Buttercup; the sepals spreading, so that the name is not appropriate, as it is to the _European Globe-flower_ of the gardens, nor is the blossom showy, being pale greenish-yellow, or nearly white. 13. CÓPTIS, Salisb. GOLDTHREAD.