Flora of North America species comparison

usually 1, usually erect, (terete or 4-angled, often striate or sulcate) branched distally or ± throughout.

(sometimes in 3s or 4s) sessile;

blades obovate or elliptic to lanceolate or linear, (20–)50–100(–160+) × (5–)10–25(–40+) mm, bases cuneate to rounded, margins usually coarsely dentate to serrate, sometimes ciliate, apices acute to acuminate, faces glabrous.

usually cauline; usually opposite, rarely whorled, distal sometimes alternate; petiolate or sessile;

blades simple, compound (leaflets petiolulate), or 1–3+-pinnatisect or -pinnately lobed (submerged leaves multifid in B. beckii, an aquatic), ultimate margins entire, dentate, laciniate, serrate, or toothed, faces usually glabrous, sometimes hirtellous, hispidulous, pilosulous, puberulent, scabrellous, or strigillose.

(10–)20–60 mm.

turbinate to hemispheric or broader, (4–)6–8(–10+) × 8–12+ mm.

mostly hemispheric or campanulate to cylindric, (1–)4–12(–25+) mm diam.

flat or slightly convex, paleate;

paleae usually falling, (usually stramineous, sometimes yellow to orange, with darker striae) ± flat to slightly navicular.

usually 7–8, rarely 0;

laminae orange-yellow, (10–)15–25(–30) mm.

usually 1–21+ (often 3, 5, 8, or 13), sometimes 0, usually neuter, sometimes styliferous and sterile;

corollas usually yellow, sometimes white or pinkish.

(25–)60–100(–150+);

corollas yellow to orange-yellow, 3–6.5 mm.

(5–)12–60(–150+), bisexual, fertile;

corollas usually yellow to orange, sometimes whitish [purplish], tubes shorter than throats, lobes (3–)5, ± deltate (staminal filaments glabrous; style-branch appendages deltate or lanceolate to subulate).

8–12, ovate or obovate to lance-oblong, (4–)6–8(–10+) mm (tips often orange to purplish, as are tips of paleae).

persistent, mostly (4–)8–21(–30+) in ± 2 series, usually distinct, sometimes connate 0.05–0.1 their lengths, mostly oblong or ovate to lance-oblong, chartaceous to membranous or scarious (usually striate with brownish nerves, margins usually hyaline).

of 5–7(–9+) erect or spreading to reflexed, oblanceolate or lanceolate to linear, often foliaceous bractlets or bracts (6–)10–12(–20+) mm, margins usually ciliate, abaxial faces glabrous or bases hispidulous.

of (3–)5–13(–21+) erect to spreading or reflexed, ± herbaceous (sometimes foliaceous) bractlets or bracts (sometimes surpassing phyllaries).

(erect at flowering, sometimes nodding in fruit) borne singly or in open, ± corymbiform arrays.

usually radiate or discoid, sometimes ± disciform, usually in corymbiform arrays, sometimes in 2s or 3s or borne singly.

blackish, red-brown, or stramineous, obcompressed, flattened or unequally 3–4-angled, ± cuneate, outer 6–8 mm, inner 8–10 mm, margins retrorsely ciliate or barbed, apices ± truncate to convex, faces ± 1-nerved, ± striate, glabrous;

pappi of 2–4 ± erect, retrorsely barbed awns 3–5 mm.

usually obcompressed to flat, unequally 3–4-angled, and cuneate to oblanceolate or obovate, sometimes (all or inner) ± equally 4-angled and linear-fusiform, rarely subterete, margins (± corky-winged in B. aristosa, B. cernua, and B. polylepis) usually retrorsely, sometimes patently or antrorsely, barbed or ciliate, apices sometimes attenuate, not beaked [beaked], faces smooth, striate, or ± tuberculate, glabrous or hairy, each sometimes with 2 grooves;

pappi 0, or persistent, of (1–)2–4(–8) usually retrorsely, sometimes antrorsely, barbellate or ciliate, rarely smooth, awns.

= 13.

= 22, 24.