Flora of North America species comparison

single, greenish when young, becoming tan to gray, fastigiately branched (± angled from leaf bases), glabrous or scabridulous.

erect to ascending, often fastigiately or intricately branched (bark typically tan, becoming white to tan or gray when older; twigs usually greenish), glabrous or scabrous, gland-dotted (sometimes in pits), often resinous.

ascending;

blades with midnerves plus 2 fainter collateral nerves evident, broadly linear to lanceolate or oblong, 20–75 × 3–8 mm, flat, margins scabrellous, apices acute to acuminate, faces glabrous, gland-dotted (in shallow pits).

cauline (usually persistent; often crowded, appressed or ascending to spreading, becoming deflexed); alternate;

sessile or petiolate;

blades prominently 1-nerved plus sometimes 1–2 pairs of collateral nerves, linear to oblong or lanceolate to narrowly oblanceolate or broadly spatulate (flat to concave), margins entire or coarsely serrate, sometimes ciliate, faces glabrous or scabrous, gland-dotted (sometimes in ± deep, resin-filled pits, sometimes sessile) or pustulate, often ± resinous.

obconic, 4.5–7 × 1.5–2.2 mm.

cylindric to obconic or hemispheric, (4–15 ×) 1.5–6 mm.

with 0–2 scales, 0–0.5 mm.

convex, pitted, epaleate (sometimes bearing scales or awn-like projections).

0.

0 or (1–)6–20, pistillate, fertile;

corollas pale to dark yellow.

(4–)5(–6);

corollas 4–5.5 mm, glabrous, lobes 1–1.5 mm;

style branches 1.9–2.3 mm, appendages subulate, 0.7–1.1 mm.

4–63, bisexual, fertile;

corollas pale to dark yellow, tubes usually shorter than (about equaling in L. salicina) gradually dilated throats, lobes 5, spreading to recurved, lanceolate to triangular;

style-branch appendages lanceolate or attenuate to subulate.

15–18 in 3–4 series, in 5 vertical ranks, mostly tan, midnerves evident on distal 1/2, ± keeled, elliptic to lanceolate, 0.7–6.5 × 0.5–1.1 mm, unequal, outer often thickened and herbaceous subapically, apices acute, acuminate, or rounded, faces glabrous or sparsely scabrous.

13–30 in 3–6 series (often in vertical ranks), green to tan, 1-nerved (midnerves obscure or evident, sometimes enlarged subapically and glandular; usually flat or convex, sometimes keeled), ovate to oblong or lanceolate to oblanceolate, strongly unequal or subequal, mostly chartaceous, outer sometimes herbaceous or herbaceous-tipped, margins scarious (apices erect or slightly spreading, acute, acuminate, cuspidate, or obtuse), faces often resinous, sometimes stipitate-glandular (in L. peirsonii).

in corymbiform arrays 3–12 cm wide.

discoid (radiate in L. microcephala and L. peirsonii; rays occasionally observed in L. spathulata), usually in congested, rounded, compound, usually cymiform to corymbiform, sometimes racemiform arrays.

tan to brownish, subcylindric, 2.5–3.5 mm, 10–12-ribbed, densely hairy;

pappi whitish tan, 4.5–7 mm.

(mostly tan to brownish) oblong to obconic, subterete to prismatic, 4–12-ribbed, faces glabrous or densely hairy;

pappi persistent, of 20–80+ tan subequal, fine, barbellate, apically ± clavate bristles in 1 series.

= 9.

= 18.