비름속 Amaranthus LINN.

1. 열매는 수평으로 또는 불완전하게 갈라진다.

2. 잎겨드랑이에 가시가 있다 ············································································································275. 가시비름

2. 잎겨드랑이에 가시가 없다

3. 화피 열편과 수술은 5개씩이며 포가 뚜렷하다.

4. 꽃차례는 녹색이며 선다. 포는 화피 열편 길이의 1.5~2 배이고 종자는 검다 ···············································273. 털비름

4. 꽃차례는 홍색 또는 백색이며 밑으로 처진다 화피 열편과 포편의 길이는 거의 같고 종자는 희며 가장지리가 적색이다 ··········274. 줄맨드라미

3. 화피 열편은 3 개， 수술은 2~3 개이고 포는 뚜렷하지 않다.

5. 꽃차례는 잎겨드랑이에 모여달리며 잎은 홍색 · 황색이다  ···································································276. 색비름

5. 꽃차례는 길게 자라고 잎은 녹색이다 ·······························································································277. 비름

1. 포과는 벌어지지 않는다. 포는 화피 열편보다 짧다.

6. 열매에 주름이 있고 정생화서는 길다 ·································································································278. 청비름

6. 열매에 주름이 없거나 적다.

7. 잎은 너비 2.5~4cm 이며 끝이 약간 파지고 줄기는 처음에 비스듬히 자라다가 곧추 선다    ·······························279. 개비름

7. 잎은 너비 0.5~2cm로서 끝이 파지지 않고 지면으로 뻗어간다   ·······························································280. 눈비름