As with all clovers, the suckling clover has trifoliate leaves, for example, each leaf has three leaflets. They are generally smaller than the leaves of white clover (Trifolium repens) and subterranean clover (Trifolium subterraneum), the other two clovers commonly found in New Zealand turf, and usually don’t have the white crescent markings on the leaflets found in these other two species.
However, size isn’t always the best way to tell species apart, as white clover leaves can get very small under some mowing and growing conditions. Both white clover and suckling clover have no hairs on their foliage whereas subterranean clover foliage is hairy.
White clover is a perennial species with stolons, so the creeping stem has roots along it holding it to the soil. Suckling clover stems, which are sometimes reddish in colour, do not have these roots. The central leaflet of the suckling clover leaflet is usually on a slightly longer stalk than the other two leaflets, unlike in white or subterranean clovers.
Medicks such as bur medick (Medicago nigra), spotted bur medick (Medicago arabica) and black medick (Medicago lupulina) also have their central leaflet on an even longer stalk than the other two leaflets.
When flowering, the suckling clover can be differentiated from white and subterranean clovers by having small clusters of yellow florets, whereas florets are white in these other two species.
The three medick species also have clusters of yellow florets like this, but the leaflets are slightly different in shape and usually much larger than those of suckling clover. As suggested by their names, the bur medicks have prickly burs when they form fruits and black medick has black seed pods, whereas the fruits on suckling clover are fairly small.