This ubiquitous European import grows almost anywhere the grass isn’t mowed too frequently. It keeps blooming throughout the season: this flower was going strong in early November in Beechview. It came to America as a pasture crop, and soon found that it really liked our open spaces.

Gray describes the genus and the species:

TRIFOLIUM [Tourn.] L. CLOVER. TREFOIL
Calyx persistent, 5-cleft, the teeth usually bristle-form. Corolla mostly withering or persistent; the claws of all the petals, or of all except the oblong or ovate standard, more or less united below with the stamen-tube; keel short and obtuse. Tenth stamen more or less separate. Pods small and membranous, often included in the calyx, 1-6-seeded, indehiscent, or opening by one of the sutures. Tufted or diffuse herbs. Leaves mostly palmately (sometimes pinnately) 3-foliolate; leaflets usually toothed. Stipules united with the petiole. Flowers in heads or spikes. (Name from tres, three, and folium, a leaf.)

T. PRATENSE L. (RED C.) Perennial; stems ascending, somewhat hairy; leaflets oval or obovate, often notched at the end and marked on the upper side with a pale spot; stipules broad, bristle-pointed; heads ovoid, sessile or not rarely pedunculate; corolla magenta to whitish; calyx soft-hairy. Fields and meadows; extensively cultivated. (Introd. from Eu.)

The height of its season is the late spring and early summer, but don’t count White Sweet Clover out at any season. This plant was sticking its head through a chain-link fence in Beechview in early November. Imported for fodder, White Sweet Clover and the similar yellow species M. officinalis (almost indistinguishable until the flowers appear) have made themselves at home here to such an extent that some regard them as pests. Nevertheless, as nitrogen-fixers that cattle like to eat, they give us a lot in return for the inconvenience they cause us.

Gray takes Melilotus as feminine, though modern botanists have conspired to claim the name for the masculine side. He describes the genus and species:

MELILOTUS [Tourn.] Hill. MELILOT. SWEET CLOVER.
Flowers much as in Trifolium, but in spike-like racemes, small. Corolla deciduous, free from the stamen-tube. Pod ovoid, coriaceous, wrinkled, longer than the calyx, scarcely dehiscent, 1-2-seeded. Annual or biennial herbs, fragrant in drying, with pinnately 3-foliolate leaves. (Name from meli, honey, and lotos, some leguminous plant.)

M. ALBA Desr. (WHITE M.) Tall; leaflets narrowly obovate to oblong, serrate, truncate or emarginate ; corolla white, 4-5 mm. long, the standard longer than the other petals pod 3-4 mm. long, somewhat reticulate. Rich soil, roadsides, etc., common. (Nat. from Eu.)

A vine that twines its way through the underbrush along creeks and streams, dangling clusters of flowers in white, pink, or purple. These flowers produce seeds, but the vine also grows less showy flowers near the ground that turn into a single underground seed, like a peanut. This vine was found in Bird Park in Mount Lebanon.

Gray describes the genus (listed as Amphicarpa) and species (listed as A. monoica):

AMPHICARPA Ell. HOG PEANUT
Flowers of 2 (or 3) kinds; those of the racemes from the upper branches perfect; those near the base and on filiform creeping branches with the corolla none or rudimentary, and few free stamens, but fruitful; reduced flowers of slightly different form sometimes also on aerial racemes. Calyx about equally 4 (rarely 5)-toothed. Stamens diadelphous. Pods of the upper flowers, when formed, somewhat scimiter-shaped, stipitate, 3-4-seeded; of the lower ones commonly subterranean and fleshy, obovate or pear-shaped, ripening usually but one large seed. Low and slender perennials; the twining stems clothed with brownish hairs. Leaves pinnately 3-foliolate; leaflets rhombic-ovate, stipellate. Petals purplish. Bracts persistent, round, partly clasping, striate. as well as the stipules. (Name from amphi, both, and karpos, fruit, in allusion to the two kinds of pods.) FALCATA Gmel.

A. monoica (L.) Ell. Leaflets thin, 1.3-5 cm. long; racemes nodding; calyx of the upper flowers 4 mm. long; the ovary glabrous except the mostly appressed hairy margin; pod 2.5 cm. long; ovary and pod of the rudimentary flowers hairy. (Falcata comosa Am. auth.; Glycine comosa L. ?) Rich damp woodlands, common. Aug., Sept.