Flora Pittsburghensis

Category: Leguminosae

  • Hog Peanut (Amphicarpaea bracteata)

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    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.

  • Everlasting Pea (Lathyrus latifolius)

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    Sometimes called Perennial Sweet Pea. These weedy vines cover hillsides in residential neighborhoods, often where they had been planted generations before. Once you have Everlasting Peas, you have them forever. But is that such a bad thing?

    From Gray’s Manual of Botany: 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 D. C. (Introd. from Eu.)

    (This was from the 1908 edition. The 1890 edition does not list Lathyrus latifolius, suggesting that it had not yet become established as a frequent escape.)

  • Crown Vetch (Securigera varia)

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    Wherever there are hillsides that no one wants to mow, there is crown vetch. Its cheerful vigor means that it often escapes and invades a hillside on its own, but its happy clover-like pink flower heads make us willing to forgive its bad manners.

  • White Clover (Trifolium repens)

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    You see it everywhere, but do you ever stop to look at it close up? This is your chance. Take a moment to contemplate the beauty of white clover in an ordinary lawn.

  • Birdfoot Trefoil (Lotus corniculatus)

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    The bright, pure yellow of these ubiquitous roadside flowers is hard to equal. Close up, the perfect little pea flowers reveal contrasting red stripes.