Medicago sativa L. - Alfalfa
Family - Fabaceae
Stems - To 1m tall, 4-angled, erect or ascending, glabrous to pubescent, multiple from base, branching, herbaceous, from taproot.
Leaves - Alternate, trifoliolate, petiolate, stipulate. Stipules lanceolate, to +1cm long, toothed to entire. Leaflets typically oblanceolate, obovate or oblong, toothed to entire, to +2cm long, -1cm broad, typically mucronate, glabrous to sparse arachnoid pubescent below.
Inflorescence - Compact axillary pedunculate racemes, with up to 40 flowers. Peduncle to +/-3cm long, typically pubescent. Cluster globose to subglobose.
Flowers - Corolla purple to whitish, papilionaceous, to 1cm long. Standard to 1cm long, 5mm broad. Stamens diadelphous. Calyx tube to 5mm long, 2mm in diameter, 5-lobed, typically glabrous. Lobes attenuate, to 4mm long, equal to subequal.
Fruits - Coiled pods to 8mm long.
Flowering - May - September.
Habitat - Waste ground, disturbed sites, roadsides, railroads. Also cultivated.
Origin - Native to Eurasia.
Other info. - M.
sativa is the only species of Medicago
in Missouri with purple flowers. As you can see from the above photos,
the flowers are variable in color. The flowers of some cultivated plants
can be greenish-yellow also. Some plants may also have fruits which are
only slightly coiled to straight.
Photographs taken somewhere in North Carolina, 5-16-03.