Heterotheca grandiflora |
Heterotheca fulcrata |
|||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
silk-grass goldenaster, telegraph weed |
mountain camphorweed, rockyscree false goldenaster |
|||||||||||||
Habit | Annuals, biennials, or short-lived perennials, 10–250 cm (atypical, spring-blooming, dwarf dune plants have short stems; perennating from proximal stem nodes in south; aromatic); taprooted. | Perennials, 17–50(–80) cm; taprooted. | ||||||||||||
Stems | 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. |
1–30+, ascending to erect (sometimes reddish brown), sparsely to densely hispido-strigose, sparsely to densely stipitate-glandular. |
||||||||||||
Leaves | 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. |
proximal cauline subpetiolate to sessile, blades oblanceolate, (13–)22–46(–60) × (3.5–)5.3–10(–14) mm, bases attenuate to somewhat rounded, margins entire, strigoso-ciliate (with a few longer hispid cilia near bases), apices mucronate, faces sparsely to densely strigoso-canescent, sparsely to moderately stipitate-glandular; distal sessile, blades ovate to lanceolate, 12–34(–55) × 4–15 mm, little reduced to larger distally, margins entire to somewhat irregularly sinuate, sparsely to densely hispido-strigose (large cilia few to numerous, usually along much of margins, sometimes just proximally), faces sparsely to densely strigose, sparsely to densely stipitate-glandular (sometimes more glandular than more proximal blades). |
||||||||||||
Peduncles | 10–65 mm, sparsely to densely hispido-strigose, densely stipitate-glandular; bracts 0–3, linear-lanceolate to linear, reduced distally. |
1–20 mm, sparsely to densely strigoso-canescent, sparsely to moderately stipitate-glandular; bracts 1–4, proximal ovate to narrowly lanceolate (bases sometimes attenuate and winged short-subpetiolate), leaflike, distalmost often distinct from distal leaves, usually subtending or just proximal to and usually surpassing heads (obscure in narrow-leaved, hairy plants). |
||||||||||||
Involucres | campanulo-hemispheric, 6–9 mm. |
cylindric to campanulate, 5.7–9(–10.3) mm. |
||||||||||||
Ray florets | 20–40; laminae 5–8 × 1–2 mm. |
(5–)11–21(–34); laminae (7–)9–13(–16) × 1–2.7 mm. |
||||||||||||
Disc florets | 30–75; corollas 4–6 mm, lobes 0.5–0.8 mm. |
(12–)26–66(–110); corollas barely ampliate, 5–7.5 mm, glabrate, lobes 0.4–0.9 mm, sparsely hairy (hairs 0.05–0.2(–0.3) mm). |
||||||||||||
Phyllaries | in 4–6 series, linear-lanceolate, unequal, margins scarious, faces strigose, densely stipitate-glandular. |
in 4–5 series, lanceolate to linear-lanceolate, unequal (outer lengths 1/4–1/3 inner), scarious, faces sparsely to moderately strigose, sparsely stipitate-glandular. |
||||||||||||
Heads | 10–110+, in corymbiform arrays, becoming paniculiform with age, branches ascending, usually relatively short compared to plant height. |
(1–)7–15(–43), in open to compact, corymbiform arrays. |
||||||||||||
Cypselae | 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(–4) mm, ribs 10–12 (sometimes golden brown to brown), faces sparsely to moderately strigose; pappi off-white, outer of linear scales 0.25–1 mm, inner of 35–45 bristles (4.3–)5–6.5(–8) mm, longest acute to weakly clavate. |
||||||||||||
2n | = 18. |
= 18, 36 (atypical plants). |
||||||||||||
Heterotheca grandiflora |
Heterotheca fulcrata |
|||||||||||||
Phenology | Flowering Apr–Dec(–Jan). | |||||||||||||
Habitat | Sandy and gravelly soils, dunes, disturbed ground, roadsides, vacant lots, fields | |||||||||||||
Elevation | 0–100(–900) m (0–300(–3000) ft) | |||||||||||||
Distribution |
AZ; CA; NV; UT [Introduced in Pacific Islands (Hawaii)]
|
AZ; CO; ID; NM; NV; TX; UT; WY; n Mexico
|
||||||||||||
Discussion | 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.) |
Varieties 4 (4 in the flora). Heterotheca fulcrata is distinguished by the one to several, usually distinctive, ovate-lanceolate bracts subtending at least some heads of the arrays; the bases of the bracts are attenuate to sometimes winged-subpetiolate. In plants with large, ovate distal leaves, the bracts are sometimes hidden by the leaves. Rarely, such bracts are missing below most heads or only one is present, making identification problematic, but the leaf margins usually harbor large hispido-strigose cilia along much of their length. The density of hairs and glands on leaves, the size and shape of leaves, and the number of florets vary greatly within the species. Four varieties are recognized on the basis of differences in those traits and in the frequency of large hispido-strigose hairs along the leaf margins. All four are sympatric along the Mogollon Rim and in the mountains south of the escarpment, in southeastern Arizona and adjacent New Mexico. Intermediate forms occur throughout the range; pure and mixed varietal populations occur in areas of sympatry. Plants in southern Idaho, northern Nevada, and northern Wyoming are atypical and easily misidentified as aberrant forms of H. villosa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||
Key |
|
|||||||||||||
Source | FNA vol. 20, p. 235. | FNA vol. 20, p. 242. | ||||||||||||
Parent taxa | Asteraceae > tribe Astereae > Heterotheca | Asteraceae > tribe Astereae > Heterotheca | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Synonyms | H. floribunda | Chrysopsis fulcrata | ||||||||||||
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 315. (1840) | (Greene) Shinners: Field & Lab. 19: 71. (1951) | ||||||||||||
Web links |