털비름 (Amaranthus retroflexus L.) 

1. 화피와 수술이 5개; 포가 화판보다 길다............... 털비름

4. 줄기가 옆으로 뻗거나 눕는다.; 잎폭이 0.5-2Cm; 화피는 평활하다........................ 눈비름 

1a. Tepals 3, rarely 2 or 4; stamens 3; utricles indehiscent.

2a. Fruit indehiscent.

3a. Stem erect, somewhat branched; utricles very rugose ........................................................................................ 13. A. viridis(청비름)

3b. Stem ascending, much branched (frequently at base); utricles smooth or slightly rugose ............................... 14. A. blitum

2b. Fruit circumscissile.

4a. Tepals 4, rarely 5 ............................................................................................................................................. 12. A. blitoides

4b. Tepals 3, rarely 2.

5a. Tepals conspicuously longer than fruit ........................................................................................................ 9. A. tricolor(색비름)

5b. Tepals ca. as long as or shorter than fruit.

6a. Stamens longer than perianth; bracts conspicuously longer than perianth ............................................ 10. A. albus(미국비름)

6b. Stamens shorter than perianth; bracts ca. as long as or shorter than perianth ........................ 11. A. roxburghianus

7a. Stamens 2, rarely 3 ............................................................................................................................................. 8. A. taishanensis

7b. Stamens 5.

8a. Armed at leaf axils; bract often becoming 2 spines, rarely 1 ........................................................................... 7. A. spinosus(가시비름)

8b. Unarmed at leaf axils; bract not becoming spiny.

9a. Plants hairy.

10a. Fruit enveloped in persistent perianth ........................................................................................... 5. A. retroflexus(털비름)

10b. Fruit longer than perianth .................................................................................................................. 6. A. hybridus(긴털비름)

9b. Plants glabrous or nearly so.

11a. Complex thyrsoid structures pendulous; bracts and bracteoles inconspicuously pointed at apex ................................................................................................................................................... 1. A. caudatus(줄맨드라미)

11b. Complex thyrsoid structures erect; bracts and bracteoles conspicuously pointed at apex.

12a. Herbs high, to 2 m tall; leaf blade paler and pubescent on abaxial veins ................................. 2. A. patulus(가는털비름)

12b. Herbs short, 0.1-0.8 m tall; leaf blade not pale, glabrous.

13a. Tepals ca. as long as or longer than fruit; bracts ca. 2 × as long as perianth ............................................................................................................. 3. A. hypochondriacus

13b. Tepals distinctly shorter than fruit; bracts ca. 1.5 × as long as perianth ........................ 4. A. cruentus