Key - FSUS

1 Inflorescence a spike; [s. TX]; [subgenus Littaea]

(c) Fortnash, Jade - CC0

(c) Shaw, Joey

(c) Frade, Duarte - CC-BY

1 Inflorescence a panicle; [FL or escaped from cultivation throughout our region]; [subgenus Agave]

(c) Frade, Duarte - CC-BY

2 Terminal leaf spine decurrent (the tough spine tissue extending down the margins of the leaf); [mostly TX, also rare in FL].

(c) alessandradalia - CC-BY-SA

3 Leaves entire or with marginal prickles towards the base of the leaf; [rare in FL and s. TX]

Agave weberi

3 Leaves with stout marginal spines from base to tip; [s. TX and frequently planted but rarely escaping cultivation elsewhere].

4 Leaves mostly reflexed, 6-10 dm long, scabrous; marginal teeth 8-15+ mm long, usually deflexed along lower leaf edge; flowers 6-8 cm long, peduncles 8-14

Agave asperrima ssp. asperrima

(c) Campbell, Kyle - CC-BY-ND

(c) Frade, Duarte - CC-BY

4 Leaves occasionally reflexed, 8-20 dm long, smooth; marginal teeth 5-10 mm long, nearly straight or undulate to crenate; flowers 7-10 cm long, peduncles 15-35.

(c) Frade, Duarte - CC-BY

5 Leaves 10-20 dm long, 6-10× as long as wide; capsules 4-8 cm long

Agave americana ssp. americana

(c) González, Ma. Eugenia Mendiola - CC-BY-SA

5 Leaves 8-13.5 dm long, 4-6× as long as wide; capsules 3.5.4 cm long

Agave americana ssp. protamericana

2 Terminal leaf spine truncate (the tough spine tissue ending abruptly, at essentially a right angle to the axis of the leaf).

(c) - CC0

6 Leaves mostly recurved

Agave desmetiana

(c) Shaw, Joey

6 Leaves straight, erect to ascending