Heterotheca subaxillaris (Lam.) Britton & Rusby

Camphorweed (en)

Species

Angiosperms > Asterales > Asteraceae > Heterotheca

Characteristics

Annuals or biennials, 10–200 cm (aromatic); taprooted (rarely perennating in south from proximal stem nodes). Stems 1–4+, procumbent to erect (sometimes reddish brown, proximal to distal branches well developed in larger plants), sparsely to densely hispido-strigose, sparsely to densely stipitate-glandular. Leaves: basal and proximal rarely persisting to flowering, sometimes present and withered, brown to black; basal to mid cauline petiolate (petioles 10–40 mm, bases auriculate-clasping), blades ovate to elliptic or lanceolate, 10–70 × 6–55 mm, bases cuneate to attenuate, margins flat or undulate, coarsely serrate or entire, basally long-ciliate, apices acute, faces moderately hispido-scabrous; distal sessile, blades ovate to lanceolate, 10–90 × 2–20 mm, reduced distally, bases often becoming cordate distally, subclasping or not clasping, margins entire, faces sparsely to moderately hispido-strigose, sparsely to densely stipitate-glandular. Heads 3–180+ in corymbo-paniculiform arrays, sometimes becoming profusely branched (loosely paniculiform or broadly corymbiform in larger plants), branches ascending to spreading. Peduncles 2–35 mm, sparsely to densely hispido-strigose, moderately to densely stipitate-glandular; bracts 0–4, proximal leaflike, ovate to lanceolate, reduced distally and becoming linear, faces sparsely to moderately hispido-strigose, sparsely to densely stipitate-glandular. Involucres hemispheric to campanulate, 4–8(–10) mm. Phyllaries in 4–6 series, lanceolate, sometimes strongly unequal, margins scarious and distally strigoso-ciliate, faces sparsely to densely stipitate-glandular, with 0–28 coarse, scabro-strigose hairs distally. Ray florets 15–35; laminae 3–7(–9) × 1–2 mm. Disc florets 25–60; corollas weakly ampliate, 2–9 mm, proximal throats glabrous to sparsely short-strigose, lobes 0.5–0.7 mm, glabrous. Cypselae dimorphic, obconic, ribs 2–3, (ray) triangular in cross section, 1.5–2.5 mm, faces glabrous to slightly strigose, (disc) laterally compressed, 2–4 mm, faces moderately to densely strigose; pappi 0 (ray) or (disc) tan to rust, outer of linear to triangular scales 0.25–0.6 mm, inner of 25–45 bristles 4–9 mm, longest weakly clavate. 2n = 18.
More
Taprooted, weedy annual or biennial 2–25 dm, erect or in some habitats low and spreading, glandular, especially above, and spreading-hairy; lvs ovate or oblong, dentate or subentire, the lower ones petiolate (some with a stipule-like basal expansion of the petiole), deciduous, the middle and upper sessile and clasping; invol 6–8 mm, its bracts finely glandular, and usually slightly hairy at the tip; 2n=18. Dry, often sandy places; Del. to Fla., w. to Kans. and Mex., and adventive n. to L.I. July–Sept.
Life form annual
Growth form herb
Growth support free-standing
Foliage retention deciduous
Sexuality hermaphrodite
Pollination -
Spread -
Mature width (meter) -
Mature height (meter) 0.1 - 2.0
Root system tap-root
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

Light 7-9
Soil humidity 1-5
Soil texture 3-6
Soil acidity -
Soil nutriment -
Hardiness (USDA) 5-10

Usage

Uses animal food medicinal
Edible -
Therapeutic use Itch (unspecified)
Human toxicity -
Animal toxicity -

Cultivation

Mode -
Germination duration (days) 3 - 10
Germination temperacture (C°) 21
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Habit

Heterotheca subaxillaris habit picture by Heather Anne Walter (cc-by-sa)
Heterotheca subaxillaris habit picture by Matthias Foellmer (cc-by-sa)

Leaf

Heterotheca subaxillaris leaf picture by Trap Hers (cc-by-sa)
Heterotheca subaxillaris leaf picture by ofirmgr (cc-by-sa)
Heterotheca subaxillaris leaf picture by Heather Anne Walter (cc-by-sa)

Flower

Heterotheca subaxillaris flower picture by D. Fox (cc-by-sa)
Heterotheca subaxillaris flower picture by Xeve Dor (cc-by-sa)
Heterotheca subaxillaris flower picture by ofirmgr (cc-by-sa)

Fruit

Heterotheca subaxillaris fruit picture by Matthias Foellmer (cc-by-sa)

Distribution

Heterotheca subaxillaris world distribution map, present in Mexico and United States of America

Identifiers

LSID urn:lsid:ipni.org:names:121478-2
WFO ID wfo-0000002565
COL ID 7VD56
BDTFX ID -
INPN ID -
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Inula subaxillaris Calycium scabrum Heterotheca chrysopsidis Heterotheca latifolia Heterotheca psammophila Heterotheca scabra Inula scabra Calycium divaricatum Stelmanis scabra Chrysopsis scabra Diplopappus scaber Heterotheca lamarckii Heterotheca subaxillaris var. latifolia Heterotheca latifolia var. macgregoris Heterotheca latifolia var. latifolia Heterotheca subaxillaris var. psammophila Heterotheca subaxillaris subsp. latifolia Heterotheca latifolia var. arkansana Heterotheca scabra var. scabra Heterotheca subaxillaris var. subaxillaris Heterotheca subaxillaris subsp. subaxillaris Heterotheca subaxillaris var. petiolaris Heterotheca subaxillaris var. procumbens Heterotheca subaxillaris