Heterotheca grandiflora
Heterotheca sessiliflora
silk-grass goldenaster, telegraph weed
golden aster, sessileflower false goldenaster, sessileflower 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+, decumbent to ascending or erect (sometimes ± brittle, sometimes reddish brown), moderately to densely hispido-strigose (long-spreading hairs often broken off), sometimes moderately hairy and densely stipitate-glandular distally (axillary leaf fascicles sometimes 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.
margins flat to strongly undulate;
basal and proximal usually withering by flowering;
proximal cauline subsessile, blades oblanceolate, (8–)15–40(–60) × (2.4–)4–8(–11) mm, bases cuneate, margins entire, strigoso-ciliate (proximal hairs longer, spreading), apices acute, faces moderately to densely hispido-strigose;
distal sessile, blades usually narrowly to broadly lanceolate, sometimes oblanceolate, 6.5–40 × 1.5–8 mm, usually reduced distally, bases rounded, faces sparsely to densely hispido-strigose or short-strigose (5–245 hairs/mm2), sparsely to densely glandular (0–50 glands/mm2).
10–65 mm, sparsely to densely hispido-strigose, densely stipitate-glandular;
bracts 0–3, linear-lanceolate to linear, reduced distally.
2–100 mm, densely hispid, strigose, or glandular;
bracts 2–5+, proximal lanceolate, leaflike, distal reduced, phyllary-like, (2–)2.5–8.5(–13) × (0.3–)0.5–1.8(–4) mm, sometimes a few, large, leafy bracts proximal to heads.
campanulo-hemispheric, 6–9 mm.
cylindric, turbinate, or campanulate (campanulate upon drying), (6–)7.5–11(–15) mm.
20–40;
laminae 5–8 × 1–2 mm.
(4–)7–15(–24);
laminae (3.5–)4.5–10.5(–18.5) × (0.7–)1–1.7(–2.4) mm.
30–75;
corollas 4–6 mm, lobes 0.5–0.8 mm.
(9–)20–50(–81);
corollas ± ampliate, (4–)5.5–7(–9.5) mm, glabrous to glabrate, lobes 0.4–1 mm, sparsely pilose (hairs 0.1–1 mm, osteolate-celled ones often fragile).
in 4–6 series, linear-lanceolate, unequal, margins scarious, faces strigose, densely stipitate-glandular.
in 4–6 series, mid narrowly triangular, unequal (outer lengths 1/5–1/4 inner), margins hyaline, fimbriate-ciliate apically, faces very sparsely to moderately strigose, very sparsely to moderately stipitate-glandular.
10–110+, in corymbiform arrays, becoming paniculiform with age, branches ascending, usually relatively short compared to plant height.
(1–)17–36(–126) in corymbiform or paniculiform arrays, branches ascending.
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, (1.3–)2–3(–4.5) mm, ribs 6–10, faces sparsely to moderately strigose;
pappi off-white, outer of linear scales 0.25–0.5 mm, inner of 25–45 bristles 5–8(–10) mm, longest attenuate to weakly clavate.
= 18.
= 18, 36.
Heterotheca grandiflora
Heterotheca sessiliflora
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.)
Subspecies 4 (4 in the flora).
Except for Heterotheca monarchensis, H. sessiliflora is the only species in the section with long (more than 0.25 mm), fragile, osteolate-celled hairs on the corolla lobes, and it is the only species native to the central and southern coastal ranges and valleys of California. The species is divided into four subspecies and five varieties differentiated on the basis of indument features, degree of waviness of the leaf margins, and to a lesser extent, stem height and leaf shape. The treatment here is based on J. C. Semple (1996), which includes a key to and descriptions, illustrations, and distribution maps of the varieties.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Distal leaf margins distinctly undulate; disc corolla lobe hairs 0.1–1 mm | → 2 |
1. Distal leaf margins weakly undulate to flat; disc corolla lobe hairs 0.2–2.5 mm | → 3 |
2. Distal leaves green, not stiff, usually densely glandular in arrays; heads often subtended by 1–3 large, leaflike bracts equaling or surpassing them, peduncle bracts sometimes phyllary-like distally; coast, dunes of south coastal ranges, 0–100 m, s California, nw Baja California (Mexico) | subsp. sessiliflora |
2. Distal leaves whitish, stiff; heads not subtended by leaflike bracts surpassing them, bracts reduced distally; (150–)300–1800(–2200) m, Ventura e to e San Bernadino Mountains, Mt. Palomar | subsp. fastigiata |
3. Proximal stems hispid; distal leaves elliptic to lanceolate, reduced distally (in tall plants), margins sometimes somewhat undulate, faces strigoso-hispid; inland hills and valleys, c California | subsp. echioides |
3. Proximal stems sparsely hispido-strigose; distal leaves oblanceolate, margins flat, faces long-strigose, little reduced distally; dunes, headlands, Mendocino to Santa Cruz (rarely to s of Monterey), San Francisco Bay area at 10–150 m | subsp. bolanderi |
CA
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