- Annual glabrescent herb, the erect stems 0.5-3.5 dm. tall, finely glandular-pubescent above nodes. Leaf-blades oblong to nearly oval in general outline but usually strongly pinnatifid-lobed, cut nearly to midrib and the segments sometimes dentate or lobed, all narrowed to petioled bases, or the upper sometimes sessile; pedicels 15-45 mm. long; calyx becoming 8-10 mm. long, strongly plicate-angled, its lobes acute, lower shorter than and upcurving against the uppermost which is usually fully twice as long; corolla 6-13 mm. long, yellow, the throat ventrally with 2 rounded upraised ridges that partially close orifice, these and the raised palate somewhat hairy and brown-spotted or usually distally blotched, lower lip with deflexed-spreading lobes, upper lip shorter and paler, ascending-arched; anthers glabrous; stigmas slightly fimbriate; capsule 6 mm. long, not dehiscing through septum-apex.
Reference: Abrams and Furris
- A nearly glabrous annual; stem erect or ascending, freely branched from the base, 3-35 cm. high , terete or somewhat quadrangular, often tinged with red; leaves few, 1-5 cm. long, mostly long-petioled, 1-nerved, variously cut, lobed or pinnately-parted, the apex obtuse, basal leaves generally numerous and in a rosette; pedicels slender, longer than the leaves, glandular-puberulent at the base, erect in flower, becoming recurved when mature, the fruiting calyx often standing at right angles to the pedicels and about half their length; calyx oblong, .5-1.5 cm. long, more or less spotted with reddish-purple, the angles tinged with the same color, villous with shaggy white hairs below the sinuses, teeth triangular-acute, the upper one little over twice the length of the others; corolla .7-1.8 cm. long, usually with a single large reddish-brown spot on the middle lobes of the lower lip, sometimes with smaller dots below; stigma-lips unequal, style puberulent; capsule short-stipitate, oblong.
Reference: Grant 1924