Flora of North America species comparison

erect, ascending, or decumbent, unbranched or branched.

often several from base, erect, ascending, or decumbent, (unbranched or few-branched distally), (0.2–)0.4–1.6(–2) dm.

basal and cauline;

petiolate or sessile;

basal rosulate or not, petiolate or sessile, blade margins entire;

cauline petiolate or sessile, blade (base cuneate or attenuate), margins entire.

subsessile;

blade oblanceolate or linear-oblanceolate, (0.5–)0.7–1.5(–2) cm × (1–)2–4(–6) mm (gradually smaller distally), base attenuate, apex subacute.

(few- to several-flowered, sometimes corymbose or paniculate).

sepals ovate or oblong, lateral pair not saccate;

petals yellow or white [rarely pink], suborbicular, spatulate, oblanceolate, linear-oblanceolate, or, obovate (apex obtuse or emarginate);

stamens tetradynamous;

filaments not winged, uni- or bilaterally winged, appendaged, or toothed;

anthers ovate or oblong;

nectar glands (4), 1 on each side of lateral stamen, median glands absent; (placentation apical or parietal).

sepals oblong, 1.2–1.5 × 0.5–0.6 mm, stellate-pubescent (trichomes with longer rays and appearing simple near apex);

petals pale yellow, spatulate, 1.7–2 × 0.4–0.5 mm, base abruptly narrowed to claw, apex deeply emarginate, glabrous;

filaments: median pairs not toothed, slightly expanded basally, lateral pair with basal appendage to 0.5 × 0.1 mm, often apically 2-toothed, 1.4–1.7 mm;

anthers ovate, 0.1–0.2 mm.

ascending, divaricate, or reflexed, slender or stout.

ascending to suberect, straight, stout, 1–3(–4) mm, trichomes uniformly stellate.

sessile, ovate-oblong, obovate, or elliptic [obcordate, rarely globose], usually strongly flattened, latiseptate, rarely inflated;

valves each not veined (smooth), pubescent or glabrous;

replum (visible), rounded;

septum complete, (membranous, translucent, veinless);

ovules 1 or 2 [or 4–8] per ovary;

stigma capitate.

ovate-oblong, (3–)3.5–5 × (2.5–)3–4 mm, apex obtuse;

valves uniformly inflated at middle, broadly flattened at margins, densely stellate-pubescent (rays equal);

ovules 2 per ovary;

style (slender), 0.3–0.5 mm, basally stellate-pubescent.

biseriate or aseriate, flattened, winged or not, orbicular or suborbicular to ovoid;

seed coat (smooth or minutely reticulate), mucilaginous or not when wetted;

cotyledons accumbent or incumbent.

ovoid, compressed, 1.6–1.9 × 1.2–1.6 mm, margins winglike, 0.1–0.3 mm wide.

= 16.