Black medic (Medicago lupulina)
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Black medic is a low-growing summer or winter annual broadleaf plant that sometimes behaves as a short-lived perennial. It is found throughout California, except for deserts, to about 8200 feet (2500 m). Black medic is common in turf and inhabits agricultural land and disturbed areas. It is good forage for livestock and sometimes is cultivated for pasture or as a cover crop. However, black medic seed is a common contaminant in commercial alfalfa and clover seed.
Grassland, pastures, vegetable and agronomic crop fields (especially alfalfa), orchards, vineyards, gardens, lawns, roadsides and other disturbed, unmanaged places.
Cotyledons (seed leaves) are oblong, smooth, and about 1/6 to 1/3 of an inch (4–9 mm) long. The first leaf is oval and broader than it is long, with a smooth edge. True leaves are fully subdivided consisting of three egg-shaped leaflets with toothed edges and resemble leaves of the mature plant.
The main stem branches near the base. Stems grow prostrate or prostrate with tips pointing upward and can reach 1-1/3 feet (40 cm) long. The plant is hairy, especially the stems. Leaves are alternate to one another along the stem. Leaves are fully divided into three egg- to heart-shaped leaflets with somewhat toothed edges. Leaflets are about 2/5 to 7/10 of an inch (1–2 cm) long and finely toothed at the tip, which often bares a tiny, slender tooth. The stalk of the middle leaflet is longer than those of the lateral leaflets. Black medic is distinguished from California burclover by its hairy leaves; the latter has nearly hairless leaves. Also the small leaflike structures (stipules) at the bases of leaf stalks are not deeply lobed and have smooth edges or a few shallow teeth in black medic, whereas those of California burclover are deeply lobed, slender and curved.
Flowers bloom from April through July. Usually ten to twenty yellow, slender, pealike flowers densely cluster to form a rounded flower head.
Fruits are kidney-shaped pods about 1/12 to 1/8 of an inch (2–3 mm) long, strongly veined, and black at maturity. Each pod contains one seed, but does not open to release seeds.
Seeds are oval to barely kidney shaped, smooth, yellowish to olive green, about 1/12 of an inch (2 mm) long, and have a small sharp point on the concave side.
Reproduces by seed.
Related or similar plants
- California burclover, Medicago polymorpha