Stamens 12 and petals 6 on the throat of a tubular inflated or gibbous calyx. [Cuphea], in [Lythraceæ], [186]
Stamens 5–8 or 10, and petals hypogynous, or nearly so.
Ovary 3-celled. [Sapindaceæ], [115]
Ovary 5-celled. [Impatiens], &c., in [Geraniaceæ], [105]
Flowers regular or nearly so.
Stamens neither just as many nor twice as many as the petals,
Triadelphous; petals 5. [Hypericaceæ], [92]
Tetradynamous (or rarely only 2 or 4); petals 4; pungent herbs. [Cruciferæ], [61]
Distinct and fewer than the 4 petals. [Oleaceæ], [335]
Distinct and more numerous than the petals. [Sapindaceæ], [115]