Flora of North America species comparison

single, erect, villous with septate trichomes, sometimes ± glabrate, sometimes distally thinly tomentose;

branches few–many, ascending.

blades oblanceolate to elliptic or ovate, 10–40 × 1–13 cm, margins flat, finely spiny-toothed and otherwise undivided to coarsely toothed or shallowly pinnatifid, lobes broadly triangular, main spines 1–5 mm, abaxial faces white-tomentose, adaxial faces green, glabrate to villous with septate trichomes;

basal usually absent at flowering, winged-petiolate, bases tapered;

principal cauline well distributed, gradually reduced, bases narrowed, sometimes weakly clasping;

distal cauline well developed.

basal and/or cauline; alternate; ± petiolate or sessile; (leaf bases often decurrent on stems) margins usually lobed to dissected, sometimes dentate or entire (usually spiny).

0–5 cm (leafy-bracted).

ovoid to broadly cylindric or campanulate, (2–)2.5–3.5(–4) × (1.5–)2–3(–4) cm, thinly arachnoid.

flat to convex, usually epaleate (often pitted and often bristly-setose or densely hairy).

tips 4–6 mm.

0 (corollas of peripheral florets in radiant heads often notably enlarged, usually 5-lobed, sometimes zygomorphic and raylike or ± 2-lipped).

0 or (in disciform heads) in 1–3+ series;

corollas (usually present) usually yellow, sometimes ochroleucous or cyanic.

bisexual and fertile (rarely functionally staminate);

corollas yellow, cyanic, or white, usually actinomorphic, lobes 5, usually narrowly triangular to ± linear, seldom deltate (sometimes unequal, corollas then ± zygomorphic);

anther bases ± tailed, apical appendages usually oblong (filaments sometimes papillate to pilose; connate in Silybum);

styles (bisexual, fertile florets) distally enlarged or swollen, usually dilated and/or with rings of hairs at or near point of bifurcation, abaxially smooth or papillate to hairy (at least distally, sometimes ± throughout), “branches” often connate, adaxially continuously stigmatic ± to tips, apices rounded to acute, appendages essentially none.

pink to purple (white), 20–35 mm, tubes 10–16 mm, throats 5–12 mm, lobes 5–9 mm.

in 10–20 series, strongly imbricate, greenish with subapical darker central zone, ovate (outer) to lanceolate (inner), abaxial faces with a narrow glutinous ridge (milky when fresh, dark when dry), outer and middle entire, bodies appressed, spines slender, abruptly spreading, 3–4 mm;

apices of inner phyllaries spreading, narrow, flattened, entire, spines spreading, slender, 3–4 mm;

apices of inner phyllaries spreading, narrow, flattened, ± dilated, ± erose or finely serrulate.

usually persistent [readily falling], in (1–)3–5+ series, usually distinct, usually unequal, usually herbaceous (sometimes fleshy), margins (entire or denticulate to pectinate, sometimes spiny) and apices seldom notably scarious (apices often spinose or ± expanded into distinct, often fimbriate-fringed, pectinate, and/or spiny appendages).

0 (involucres sometimes closely subtended by leaflike peduncle bracts).

1–many, in corymbiform or paniculiform arrays, (± elevated above principal cauline leaves), not subtended by ring of spiny bracts.

mostly homogamous (usually discoid, sometimes disciform or radiant, then peripheral florets usually pistillate or neuter, sometimes bisexual or with staminodes), borne singly or in corymbiform, paniculiform, or racemiform arrays (heads with 1 floret each aggregated into second-order heads in Echinops).

tan to dark brown, 4–5.5 mm, apical collars stramineous, 0.5–1 mm;

pappi 12–24 mm.

usually monomorphic within heads (often thick-walled, hard, nutlike, receptacular attachments basal or lateral, bases sometimes each with an elaiosome), usually ellipsoid, obovoid, or ovoid, sometimes rounded-prismatic, terete, 4–5-angled, or ± compressed, rarely beaked, bodies usually smooth, sometimes rugose or 10- or 20-nerved (glabrous or puberulent to villous; often with apical umbo and/or crown in addition to pappus);

pappi (rarely 0) readily falling or persistent, usually of fine to coarse, barbellate to plumose bristles, sometimes of scales, sometimes both bristles and scales.

= 18.