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SWEET VETCH
Hedysarum coronarium L., family Leguminosae

Sweetvetch, sulfa, French honeysuckle, or Spanish sainfoin succeeds fairly well in a number of places where it has been tried experimentally in the United States (McKee and Pieters 1937), but it is of no significance economically. The plants are sometimes confused with some species of Astragalus, but differ by having jointed pods, gland-dotted leaves, and squarish-tipped flowers. It is relished by all classes of livestock. In southern Europe, it is used as a hay and soil-improvement crop.

Plant:

Sweetvetch is a perennial or biennial legume plant growing to 4 feet tall, with deep-red, fragrant flowers producing flat jointed pods of four or more ovules. It has pinnate leaves and deep roots (Graham 1941*) and yields an excellent honey.

Inflorescence:

The l/2 to 3/4-inch-long flowers, which resemble those of scarlet runner beans, develop in crowded axillary racemes on long peduncles. Knuth (1908*, pp. 317-318) stated that when a bee visits the flower the stigma and 10 anthers protrude from the keel and press against the ventral surface of the bee.

Pollination Requirements:

The stigma projects beyond the anthers, so it is first to emerge when pressure of the bee is applied to the flower, thus cross-pollination is assure and self-pollination is rendered difficult.

Sacchi (1950) found that plants caged to exclude bees set practically no seed, but plants exposed to bees set good crops in proportion to the bee population in the area and visitors to the flowers. Honey bees were the primary visitors. His data indicate that this crop is dependent upon insect pollinators for adequate seed set.

Pollinators:

No tests have been conducted on the relative value of different pollinators to sweetvetch; however, honey bees work the plant sufficiently to obtain a honey crop. This indicates that they probably would be effective pollinators.

Pollination Recommendations and Practices:

None.

LITERATURE CITED:

McKEE, R., and PIETERS, A. J.
1937. MISCELLANEOUS FORAGE AND COVER CROP LEGUMES. U.S. Dept. Agr. Yearbook 1937: 999-1031.

SACCHI, R.
1950. [INVESTIGATIONS ON THE ACTIVITY OF BEES AS POLLINATORS OF SULLA (SWEETVETCH). Ann. Fac. Agr., Perugia 7: 114-124. [In Italian.] Abstract in Herbage Abs. 23(3): 141, 1953.

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