Often unable to survive rapid or extreme temperature changes. Cotyledons lanceolate, 4-10 mm long, pale green, with a slightly powdery film. Stems typically branched near the top. Leaves primarily alternate, but crowded and often appearing opposite or whorled, especially near the bases of stems. Leaf margins entire.
Aboveground parts die back to the ground in fall.
Stems erect, glabrous. Generally more robust than yellow toadflax . Stems erect to ascending, usually less than 1 m tall, glabrous or glandular hairy near the top. Root fragments can produce new plants. Roots can associate with vesicular-arbuscular mycorrhizae.