1 | Annual or biennial herbs with slender stock and roots; without non-flowering shoots. |
1' | Perennials with stout stock and root; non-flowering shoots usually present at flowering time. |
2 | Bracteoles as long as calyx or longer; leaves narrowly elliptic to elliptic, at least some leaves (lower) obtuse or subobtuse. |
2' | Bracteoles much shorter than calyx; leaves narrowly elliptic to linear, all leaves acute or acuminate. |
3 | Leaves linear-narrowly elliptic, flat, 3-6 mm broad; petal blades narrow, not touching below, divided more than halfway down into very narrow, hair-like lobes. |
3' | Leaves linear, 1-3 mm broad, petal blades divided one third to halfway down into narrow but not thread-like lobes. |
4 | Whole plant not more than 35 cm tall; leaf pairs above the rosette 1-4, leaves about 1 mm broad. |
4' | Whole plant 50-80 cm tall; leaf pairs above the rosette 5-7; leaves 2-3 mm broad, nearly flat. |