Hard to tell from White Sweet Clover (M. alba) until they both bloom. When they do bloom, the yellow species reveals sloppier habits; the flower spikes are more ragged than the ones of M. alba, with withering flowers retained for a long time. Nevertheless, the delightful scent is enough to make us forget the slight slovenliness of the presentation. Yellow Sweet Clover grows plentifully along roadsides, and is often one of the first plants to colonize a recently disturbed site; this plant was growing in a park in Beechview where the earth had just been replaced after the building of a new playground. It was blooming in the middle of July.

Gray describes the genus and the species (and has anyone in history other than Asa Gray ever used the English word “melilot”?)

MELILÒTUS [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. officinalis (L.) Lam. (YELLOW M.) Upright, usually tall; leaflets obovate-oblong, obtuse, closely serrate; petals yellow, of nearly equal length. 6-9 mm. long; pod 2.5-3.5 mm. long, glabrous or glabrate, prominently cross-ribbed. — Waste or cultivated ground, common. (Nat. from Eu.)

A European import cultivated for fodder, Cow Vetch tends to be found wherever livestock is nearby. The vines twine through other less decorative weeds, and the beautiful blue-purple flowers light up the edges of fields. This patch grew in a sunny meadow near Cranberry, where it was blooming in the middle of June.

Gray describes the genus and the species:

Calyx 5-cleft or 5-toothed, the 2 upper teeth often shorter, or the lowest longer. Wings of the corolla adhering to the middle of the keel. Stamens more or less diadelphous (9 and 1); the orifice of the tube oblique. Style filiform, hairy all round or only on the back at the apex. Pod flat, 2-valved, 2-several-seeded. Seeds globular. Cotyledons very thick, remaining under ground in germination. Herbs, mostly climbing more or less by the tendril at the end of the pinnate leaves. Stipules half-sagittate. Flowers or peduncles axillary. (The classical Latin name.)

V. cracca L. Appressed-pubescent; leaflets 8-24, oblong-lanceolate, strongly mucronate; racemes densely many-flowered, 1-sided; flowers blue, turning purple (rarely white), 1-1.2 cm. long, reflexed; calyx-teeth shorter than the tube. Borders of thickets or in fields, Nfd. to N. J., w. to Ky., la., and Minn. June- Aug. (Eu.)

Red Clover (T. pratense) is more common and very similar, and grows in most of the same places. The best way to tell the difference is by the leaves, which in Red Clover usually (but not always) show a chevron pattern but are unmarked in Alsike Clover; and by the color of the flowers, which in Alsike Clover is less magenta and more pale rosy pink, with young white flowers in the center of the head. In fact, it does look like something halfway between Red Clover and White Clover (T. repens), which may account for the specific name hybridus for a plant that is not a hybrid.

This plant grew in a meadow near Cranberry, where it was blooming in the middle of June.

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. HYBRIDUM L. (ALSIKE C.) Resembling T. repens, but the stems erect or ascending, not rooting at the nodes; leaflets ovate, rounded at apex; flowers rose-tinted. Generally common. (Introd. from Eu.)

Everlasting Pea is a vigorous vine that can take over whole hillsides. It compensates us for the space it takes with a glorious array of flowers in shades from white through deep magenta, often (as here) with stripes or bicolor patterns.

Gray describes the genus and the species:

Style dilated and flattish (not grooved) above, hairy along the inner side (next the free stamen). Sheath of the filaments scarcely oblique at the apex. Otherwise nearly as in Vicia. Our species perennial and mostly smooth plants. (Lathyros, a leguminous plant of Theophrastus.)

L. latifolius L. (EVERLASTING or PERENNIAL PEA.) Tall perennial with broadly winged stems; leaves and stipules coriaceous and veiny; petioles mostly winged; the 2 elliptic to lanceolate leaflets 0.5-1 dm. long; peduncles stiff, many-flowered; flowers showy, pink, purple, or white. Frequently cultivated, and escaping to roadsides and thickets, Ct. to 1). C. (Introd. from Eu.)

Another picture is here.