Flora of North America species comparison

erect to ascending, green when young, fastigiately branched, glabrous or sparsely hairy, resinous.

erect, much branched, twigs crowded, green when young, becoming reddish brown to gray, glabrous or sparsely hairy, usually covered with resin-filled pits.

ascending to spreading;

blades filiform (terete or flattened), 5–25 × 1–2 mm, midnerves obscure, apices acute often mucronate, faces glabrous or sparsely hairy, regularly gland-dotted (in circular, deep pits), resinous;

axillary fascicles of 2–10 leaves, shorter than subtending leaves.

(moderately crowded) ascending to spreading;

blades linear to narrowly oblanceolate (terete, sulcate, or flattened), 5–50 × 0.5–2 mm, midnerves obscure or evident abaxially, apices acute, faces glabrous or moderately hairy, gland-dotted (in circular, deep pits), resinous;

axillary fascicles with 1–10 leaves, shorter than subtending leaves.

1–15 mm (bracts 3+, leaflike).

2–15 mm (bracts 5–10+, leaflike).

subcampanulate, 6–8.5 × 5–7 mm.

turbinate to subcampanulate, 4–7 × 2.5–4 mm.

4–6;

laminae 4.5–6 × 1.2–2 mm.

2–8;

laminae 4–5 × 1–1.8 mm.

18–25;

corollas 6.5–8 mm.

6–20;

corollas 5–7 mm.

22–26 in 3–5 series, yellowish tan, ovate to lanceolate, 2.5–7 × 0.6–1.5 mm, unequal, mostly chartaceous, midnerves evident, sometimes with 1–2, collateral nerves, ± thickened, raised, often expanded distally, subapical resin ducts darker, narrow and only slightly thickened, (margins membranous, erose-ciliate) apices erect, acute to acuminate or cuspidate, abaxial faces glabrous or sparsely hairy.

16–24 in 3–5 series, mostly tan, narrowly oblong to elliptic, 1.5–6 × 0.4–0.8 mm, unequal, mostly chartaceous, midnerves evident on at least distal 1/2, slightly to strongly thickened, expanded distally, (margins narrowly membranous, sometimes ciliate distally) apices acute to rounded, abaxial faces glabrous, outer sometimes gland-dotted (sessile), frequently resinous.

mostly borne singly, sometimes in cymiform to racemiform arrays (4–6 cm wide).

in racemiform to thyrsiform arrays (to 50 × 2–15 cm).

tan to brown, subcylindric, 3.5–4 mm, sericeous to villous;

pappi off-white to reddish brown, 6.5–8 mm.

tan to brown, subcylindric, 3.5–4 mm, moderately to densely hairy;

pappi off-white to brown, 5–8 mm.

= 18.

= 18.