Arabidopsis thaliana, mouse-ear cress

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Intermountain Flora
Slender annual, 1-3 (4) dm tall, from a taproot; herbage hirsute, the stem hairs simple or some once-forked, the leaf hairs mostly branched; stems erect, simple or branched; leaves basal and cauline, the basal 1-2.5 cm long, 2.5-4.5 (8) mm wide, elliptic or spatulate, obtuse apically, entire or sparingly dentate, tapering to a petiolar base, the cauline leaves few, linear to narrowly oblong, entire, sessile, not auriculate; raceme frequently branched below, glabrous; sepals 1.2-1.7 mm long, ovate, obtuse; petals 2-3 94) mm long, spatulate to linear, white; fruiting pedicels divaricately ascending, 5-15 mm long; siliques 0.9-1.7 cm long, 0.5-0.7 mm wide, linear, subterete, somewhat upcurved, glabrous, the valves 1-nerved; mature style 0.3-0.5 mm long; seeds numerous in 1 row in each locule, 0.4-0.5 mm long, ovoid, yellowish-brown, cellular-roughened, the cotyledons incubent; 2n = 10.

Cronquist, A., Holmgren, N.H., and Holmgren, P.K. (2005) "Intermountain Flora" pg. 404, vol. 2 part B, The New York Botanical Garden New York.