Leaves are alternate and compound, with three leaflets. Leaflets are oblong, with a rounded tip, can be slightly hairy on underside, serrated only at tip, up to 2.5cm long. Terminal leaflet stalk (petiolule) is longer than the petiolule of the lateral leaflets, which are nearly sessile.
Purple/blue, irregular flowers. Clusters of 5 to 30 flowers arising from upper leaf axils, each flower roughly 0.8cm long, with the typical shape of the pea family.
Fruit is a coiled/spiraled pod containing up to 10 yellow/brown seeds.
Yellow lucerne (Medicago falcata)
Flowers are yellow, and fruit pods are curved, but not spiraled like M. sativa.
Black medick (Medicago lupulina)
Generally smaller than alfalfa (15-80cm tall,) with small yellow flowers.
Sweet Clover (Melilotus sp.)
Alfalfa leaflets are only serrated on the upper portion and slightly hairy on the underside, while sweet clover leaflets are serrated along most of the margin, except for the base, and hairless.
Flowers of alfalfa are usually blue or purple, and larger than those of sweet clover.
Hop Clover (Trifolium campestre)
Hop clover has yellow flowers
Birdsfoot Trefoil (Lotus corniculatus)
Trefoil has 5 leaflets.
Leaves and young shoots
Leaves can be dried and used in tea
Alfalfa should not be consumed by those with auto-immune diseases, and should not be taken in combination with blood thinners.
A major source of animal feed and hay.
Used as a cover cop due to its ability to fix nitrogen, and improve nutrient levels in soil