An Illustrated Guide to ARIZONA WEEDS
The University of Arizona Press
BLACK MEDIC, nonesuch, hop medic
BLACK MEDIC-Medicago lupulina L.
DESCRIPTION-A low trailing annual, biennial, or perennial reproducing by seeds only. The slender hairy 4-angled stems are prostrate or partly so, branching from the base and radiating out from the taproot, 1/2 to 2 feet long. The leaves are divided into 3 leaflets, very similar to those of bur clover, with the tips rounded and finely toothed, and the veins prominent. However, the central leaflet is on a short stalk.
The flowers are also pealike, small and bright yellow, about 1/8 inch long, but many are clustered together. They are crowded into short dense spikes, which are on stalks 1 to 3 inches long. The small pods are somewhat kidneyshaped, thick walled, curved, and with distinct veins, 1 1/2 to 1/8 inch long. They have no prickles, are usually hairy, black when mature, and contain only 1 seed. The small seeds, also kidneyshaped, are greenish yellow to brown, about 1/16 to 1/12 inch long, and very similar to alfalfa seed.
DISTRIBUTION-Black medic is a native of Eurasia. In Arizona it is primarily, as is bur clover, a nuisance in lawns where it thrives, and in alfalfa seed fields. It is found as a weed almost throughout the state in moist, often sterile soil along roadsides, in gardens, and waste places; up to 8,000 feet elevation; flowering from April to September. Where black medic grows in pastures or uncultivated fields, it can scarcely be classed as a weed since it is so high in forage value.
Copyright (c) 1972 The Arizona Board of Regents