Flora of North America species comparison

strictly annual, disintegrating in 1st year;

blade oblong-ovate to ovate, 25+ mm wide, leathery, base cuneate, truncate, or rounded to lobate, sometimes cordate, margins crenate, teeth apices acute to rounded, surfaces sparsely hairy;

basal veins extending into distal 1/2 of blade, lateral veins 3–6 on each side of midvein.

erect, to 45 cm in fruit;

sterile bracts 10–30, ovate-spatulate, largest 1+ cm;

flowers 100+, densely aggregated (separating in fruit).

inserted on receptacle.

ovules 17–40.

densely hairy.

4, basal connation between abaxial and adaxial lobes on each side of flower.

1–4, apex entire or erose;

corolla reddish, bluish purple, green, or white, bilabiate or unilabiate, rudimentary, much shorter than calyx, glabrous, lateral and abaxial petals of abaxial lip connate 1/2+ their lengths, abaxial and adaxial petal lips basally adnate to stamens, tube absent.