Black Medick

Legume (Fabaceae family):

Medicago lupulina L.

EPPO code:

MEDLU

Other names:

Yellow clover, lupuline, luzerne

Species information

Lifecycle:

Annual, winter annual or biennial.

Propagation:

Reproduces by seed.

Emergence:

Seeds germinate in early autumn or spring.

Habitat:

Found throughout the province in various types of soils; in cultivated fields it prefers environments with little soil disturbance, therefore is most often found in no-till or minimum till cropping systems.

Competitiveness:

Limited Ontario field trials have demonstrated as much as 20% yield losses from moderate to heavy populations.

Identification clues

Seedling

Cotyldeons:

Elongated to oblong with a rounded tip and base, stalkless.

Young leaves:

The first leaf is entire, broad oval, borne on a long stalk, the following leaves are compound trifoliolate, the central leaflet has a short stalk.

Mature leaves:

Alternate, compound trifoliolate leaves with round to wedge-shaped leaflets, each with shallow toothed margins. Like its close relative alfalfa, the middle leaflet has a longer stalk than the middle leaflets.

Mature plant

Stems:

Wiry, long and prostrate lying on the ground or short, erect and spreading.

Flowers:

Individually very small but grouped in dense clover-like, yellow clusters on long stalks; flowers from spring to autumn; seedpods resemble a bundle of small black coils.

Seeds:

Kidney-shaped, 1.5–2.5 mm long; orange to orange-brown.

Roots:

Taproot with secondary branched roots.

Often mistaken for

I know it's not Woodsorrel because woodsorrel has heart-shaped leaflets and flowers with 5 petals compared to the oval leaflets and round to egg-shaped and clustered flowers of black medick.

I know it's not Clovers because clover species have relatively similar compound leaves, but the center leaflet does not have a longer stalk.