Macroptilium lathyroides (L.) Urb.

• Title

  Macroptilium lathyroides (L.) Urb.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Macroptilium lathyroides (L.) Urb.

• Description

  Flora Borinqueña Macroptilium lathyroides Habituela parada Wild Bush Bean Family Fabaceae Pea Family Phaseolus lathyroides Linnaeus, Species Plantarum, edition 2,1018.1763. Macroptilium lathyroides Urban, Symbolae Antillanae 9: 457. 1928. With red or purple flowers in long clusters, this low, herbaceous plant is often conspicuously plentiful in fields, on banks and hillsides at lower and middle altitudes in Porto Rico, sometimes becoming a weed in cultivated grounds. Formerly classified as a species of Phaseolus, this reference has been improved by separating it and some related ones into the genus Macroptilium. The plant is distributed nearly throughout tropical America, and in tropical parts of the Old World. An albino specimen, with white flowers, was once observed by Mrs. Horne. Phasemy is another English name. Macroptilium (Greek, large wings) a genus proposed by Urban in 1928, was previously published as a subgenus of Phaseolus by Bentham in 1859. It includes about 6 species of herbs and herbaceous vines, with 3-foliolate or rarely 1-foliolate leaves, and rather large flowers clustered on long stalks. The calyx has a narrowly bell-shaped tube and usually 5 teeth or lobes; the standard petal is broad and reflexed, its apex notched; the wing-petals are broad, and longer than the standard, with long stalks adherent to the tube of stamens; the narrow keel-petals are also attached to the stamen-tube; there are 9 united stamens and 1 separate. The pods are slender. Macroptilium lathyroides (similar to some species of the genus Lathyrus), the only one of the genus growing in Porto Rico, is an upright, or ascending herb, about a meter long, or shorter, silky hairy, or nearly smooth. The narrow, long-pointed stipules are from 8 to 15 millimeters long, the leaf-stalks slender; the 3, thin leaflets vary from ovate to narrowly lance-shaped, from pointed to blunt, and from 2 to 6 centimeters long. The flowers are several or many in slender clusters from 10 to 30 centimeters long, the individual ones on very short stalks; the unequally toothed calyx is 4 or 5 millimeters long, the standard petal from 12 to 15 millimeters long. The slender, reflexed-spreading pods are from 7 to 12 centimeters long, and about 3 millimeters thick.