벼룩이자리속 Arenaria LINN.

1. 잎은 1 맥이다 ······················································································································303. 관모개미자리

1. 잎은 3맥 또는 그 이상이다.

2. 선모가 있다.

3. 잎은 길이 8-15mm 이고 꽃잎은 꽃받침의 길이와 비슷하거나 다소 짧다  ············································304. 삼수개미자리

3. 뿌리에서 돋은 잎은 길이 20 cm 정도이고 꽃잎은 꽃받침보다 길다  ··················································305. 벼룩이울타리

2. 선모가 없다. 뿌리에서 돋은 잎은 길이 1 cm 정도이고 꽃잎은 꽃받침보다 짧다   ········································306. 벼룩이자리