74 
Spring Flora of Oklahoma 
ments diadelphous. Ovary sessile or nearly so. Style 
subulate. Pod curved or spirally twisted, reticulated or 
spiny. 
Perennial; flowers violet, conspicuous. 1. M. saliva. 
Annual; flowers bright yellow, small. 2. M. lupvlina. 
1. Medicago sativa L. Alfalfa. Perennial, much branched. 
Leaves petioled. Leaflets oblanceolate or obovate, 2"-12" long, dent¬ 
ate, especially toward the apex, obtuse, cuneate at the base. Stipules 
entire. Flowers violet or blue in a dense short raceme. Pod pubes¬ 
cent, twisted into 2 or 3 spires. 
In fields and waste places. Spring and summer. Cultivated. 
2. Medicago lupulina L. Black Medic. Annual, pubescent, 
branched at the base, the branches decumbent and spreading. Leaves 
petioled. Leaflets obovate, denticulate or crenulate, narrowed or 
rounded at the base. Stipules ovate or lanceolate, dentate. Head 
oblong or cylindric, dense. Flowers bright yellow. Pods nearly 
glabrous, curved into a partial spiral, strongly veined. 
In fields and waste places. March-December. Common. 
IV. MELILOTUS (Tourn.) Mill. 
Annual or biennial herbs, with 3-foliolate, petioled 
leaves, dentate leaflets, and small, white or yellow flowers 
in slender racemes. Calyx teeth short. Standard obovate 
or oblong, wings oblong, keel obtuse. Stamens diadelphous. 
Ovary sessile or stipitate. Pod ovoid or globose, straight. 
Flowers white; standard a little longer than the wings. 
1. M. alba. 
Flowers yellow; standard about equaling the wings. 
2. M. officinalis. 
1. Melilotus alba Desb. White Sweet-clover. Glabrous, branch¬ 
ing, or young leaves and twigs finely pubescent. Leaves petioled. 
Leaflets, oblong, serrate, narrowed at the base, truncate at the apex, 
stipules subulate. Racemes numerous. Flowers white. Pods ovoid, 
slightly reticulated and glabrous. 
In waste places. Common. May-November. 
2. Melilotus officinalis (L.) Lam. Yellow Sweet-clover. Re¬ 
sembling the preceding species, but flowers yellow. Leaflets rounded 
at the apex, oblong or oval. Pod with irregularly reticulated veins, 
often slightly pubescent with appressed hairs. 
In fields and waste places. March-December. Common. 
