1. Plants fibrous-rooted perennial subshrubs; leaves leathery, entire, ± evergreen; flowering May and June.

I. sempervirens

1. Plants tap-rooted annuals; leaves herbaceous, toothed or entire, not evergreen; flowering July-September.

2. Fruit ca. 3-5 mm long; flowers usually white, fragrant; leaves ± irregularly toothed; inflorescence elongating in fruit.

I. amara

2. Fruit ca. 5.5-6.5 (-10) mm long; flowers usually pink, red, or purple, not fragrant; leaves entire; inflorescence remaining densely compact in fruit.

I. umbellata