Circumscribed here to include species formerly placed in Smilacina.

1. Perianth of 4 parts; leaves 3 or fewer (very rarely 4, usually 2), sometimes pubescent beneath.

M. canadense

1. Perianth of 6 parts; leaves often more than 3 (1-4 in one species, where completely glabrous).

2. Inflorescence a panicle; perianth 1-2.5 mm long, the stamens up to 3 mm long.

M. racemosum

2. Inflorescence a raceme; perianth 2.5-9 mm long, exceeding the stamens.

3. Cauline leaves more than 6, finely pubescent beneath (rarely almost glabrous); uppermost leaves surpassing the top of the inflorescence.

M. stellatum

3. Cauline leaves 1-4, completely glabrous; inflorescence almost always overtopping leaves.

M. trifolium