Heterotheca grandiflora
Heterotheca marginata
silk-grass goldenaster, telegraph weed
Sonora false goldenaster
1–5+, ascending to erect (strict, 0.9–1.7 cm diam., only distal lateral branches developing in larger plants), moderately to densely hispido-strigose, more so proximally, moderately to densely stipitate-glandular, more so distally.
1–40, ascending to erect (sometimes reddish brown proximally, brittle), sometimes arching, hispido-scabrous (axillary leaf fascicles often present).
basal and proximal cauline petiolate (petioles 3–7 cm, bases auriculate-clasping), blades ovate or elliptic to oblong, 50–80 × 20–30 mm, margins flat or somewhat undulate, coarsely serrate to serrulate or entire, proximally long-ciliate, apices acute, faces moderately to densely long-hispido-strigose;
distal sessile, blades oblong-lanceolate to lanceolate, 20–40 × 20–30 mm, reduced distally, margins often undulate, coarsely serrate.
cauline stiff;
proximal petiolate, blades oblanceolate, (180–)240–550 × 4–7(–9) mm, bases convex-cuneate, margins entire, strigoso-ciliate, with many long-hispido-strigose cilia all along, apices acute, mucronate, faces sparsely to moderately, coarsely hispido-scabrous, sparsely stipitate-glandular;
distal sessile, blades oblanceolate, 14–31 × 3.3–5.2 mm, reduced distally, apices acute.
10–65 mm, sparsely to densely hispido-strigose, densely stipitate-glandular;
bracts 0–3, linear-lanceolate to linear, reduced distally.
12–29 mm, moderately to densely hispido-strigose, sparsely stipitate-glandular;
bracts 0–3, linear-oblanceolate, usually greatly reduced, rarely leaflike and linear-oblanceolate, sparsely to moderately hispido-scabrous, sparsely stipitate-glandular.
campanulo-hemispheric, 6–9 mm.
campanulate, 6.5–9(–10) mm.
20–40;
laminae 5–8 × 1–2 mm.
10–15;
laminae 9–14.5 × 1-2.5 mm.
30–75;
corollas 4–6 mm, lobes 0.5–0.8 mm.
(25–)31–46(–50);
corollas barely ampliate, 4.5–7.5 mm, tubes and throats glabrate, lobes 0.4–0.9 mm, glabrous or glabrate (hairs 0.1–0.2–0.3 mm).
in 4–6 series, linear-lanceolate, unequal, margins scarious, faces strigose, densely stipitate-glandular.
in 4–5 series, narrowly triangular-lanceolate, unequal (outer lengths 1/5–1/4 inner), scarious, faces moderately strigose (larger hairs to 1 mm), eglandular to sparsely stipitate-glandular.
10–110+, in corymbiform arrays, becoming paniculiform with age, branches ascending, usually relatively short compared to plant height.
8–50(–78), in open paniculiform arrays.
dimorphic, (ray) 2–5 mm, faces glabrous or slightly strigose on angles, (disc) 4–6 mm, faces moderately to densely strigose;
pappi 0 (ray) or (disc) stramineous to rusty brown, outer bristles 0.4–0.7 mm, inner 6–9 mm, longest weakly clavate.
monomorphic, obconic, compressed, 1.5–3.2 mm, ribs 8–10 (sometimes brownish), faces moderately strigose;
pappi off-white, outer of linear scales 0.5–1 mm, inner of 35–45 bristle 4.6–7.4 mm, longest acute to weakly clavate.
= 18.
= 18, 36.
Heterotheca grandiflora
Heterotheca marginata
Heterotheca grandiflora is common in California, rare and probably introduced in Arizona, Nevada, and Utah, and introduced in Hawaii. Rosette plants can bloom in the spring.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Heterotheca marginata grows in the Superstition and Pinal mountains. It is characterized by its numerous, long, hispido-strigose hairs along the entire margins of its distal leaves and peduncle bracts. The hairs give the plants a light gray-green appearance from a distance. The leaves are stiff, unlike other taxa in the section. It is similar to H. fulcrata var. arizonica, which is more glandular and typically has narrowly ovate to lanceolate bracts subtending smaller heads, and H. fulcrata var. senilis, which can be similar in indument but typically has more ovate leaves and heads subtended by narrowly ovate to lanceolate bracts.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
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