5. C. hirsùta, L. (SMALL BITTER CRESS.) Glabrous or beset with scattered hairs; stems (3´--2° high) erect or ascending from the spreading cluster of root-leaves; their leaflets rounded, those of the upper leaves oblong or linear and often confluent, all either toothed, angled, or entire; pods linear, very narrow, erect or ascending; style variable.--Wet places; common. May--July. The ordinary form corresponds closely to the European var. SYLVÁTICA, Gaud. The typical imperfectly developed annual form, with only 4 stamens and rather strict pods, occurs very rarely. A form answering to C. parviflora of Europe, with mostly linear leaflets and pods often erect on spreading pedicels, is occasionally found in drier localities. (Eu., Asia.) 5. ÁRABIS, L. ROCK CRESS. Pod linear, flattened; placentas not thickened; the valves plane or convex, more or less 1-nerved in the middle, or longitudinally veiny. Seeds usually margined or winged. Cotyledons accumbent or a little oblique.--Leaves seldom divided. Flowers white or purple. (Name from the country, _Arabia_. See _Linn. Phil. Bot._ § 235.) § 1. ARABIS proper. _Seeds in one row in each cell, orbicular or nearly so, more or less wing-margined; cotyledons strictly accumbent._ [*] _Low, chiefly biennials, diffuse or spreading from the base._ 1. A. Ludoviciàna, Meyer. Nearly glabrous, often annual; leaves all pinnately parted into oblong or linear few-toothed or entire divisions, those of the lower leaves numerous; pedicels very short; flowers small, white; pods rather broadly linear, spreading, flat; seeds winged.--Open grounds, Va. to Mo., and southward. [*][*] _Erect and simple leafy-stemmed biennials, with simple leaves, white or whitish flowers, narrow but flattened ascending or erect pods, and nearly wingless seeds._ 2. A. pàtens, Sulliv. Downy with spreading hairs, erect (1--2° high); stem-leaves oblong-ovate, acutish, coarsely toothed or the uppermost entire, partly clasping by the heart-shaped base; petals (bright white, 4´´ long) twice the length of the calyx; _pedicels slender, spreading; pods spreading or ascending, tipped with a distinct style_.--Penn. to central Ohio and southward; Minn. April, May. 3. A. hirsùta, Scop. Rough-hairy, sometimes smoothish, strictly erect (1--2° high); stem-leaves oblong or lanceolate, entire or toothed, partly clasping by a somewhat arrow-shaped or heart-shaped base; petals (greenish-white) small, but longer than the calyx; _pedicels and pods strictly upright; style scarcely any_; immature seeds somewhat 2-rowed.--Rocks, common, especially northward. May, June. (Eu.) [*][*][*] _Erect and simple leafy-stemmed biennials (1--3° high), with small whitish flowers, recurved-spreading or pendulous flat pods (3--4´ long), and broadly winged seeds, their stalks adherent to the partition; root-leaves rarely lyrate._