Hymenoxys cooperi

(A. Gray) Cockerell

Bull. Torrey Bot. Club 31: 494. 1904.

Common names: Cooper’s rubberweed or bitterweed
Endemic
Basionym: Actinella cooperi A. Gray Proc. Amer. Acad. Arts 7: 359. 1868
Synonyms: Hymenoxys cooperi var. canescens (D. C. Eaton) K. F. Parker
Treatment appears in FNA Volume 21. Treatment on page 442. Mentioned on page 435, 436, 437.

Biennials or perennials, (10–) 20–80 (–100) cm (monocarpic; sometimes with sparingly branched, woody caudices). Stems 1–3 (–15), usually purple-red-tinted proximally, sometimes purple-red-tinted throughout, branched distally, ± hairy. Leaves: blades simple or lobed (lobes 3–9), ± hairy, glanddotted (basal leaf-bases ± long-villous-woolly); mid leaves lobed (lobes 3–5, terminal lobes 1–2.5 mm wide). Heads (1–) 7–45 (–80) per plant, in paniculiform to corymbiform arrays. Peduncles (2–) 3.5–8 (–13) cm, ± hairy. Involucres subhemispheric to hemispheric, 8–10 × 10–17 mm. Phyllaries in 2 series, unequal; outer 8–15, basally connate 1/3–1/2 their lengths (moderately to strongly keeled), lanceolate, 4.5–8.9 mm, apices acuminate to acute; inner 14–22, obovate to oblanceolate, 4.1–6.8 mm, apices acuminate to mucronate. Ray-florets 9–14; corollas yellow, 10.2–17 (–21.5) × 4–7.5 (–9.2) mm. Disc-florets 30–150+; corollas 2.7–4.8 mm. Cypselae narrowly obpyramidal, 1.7–3.7 mm; pappi of 5–6 (–8) obovate, aristate scales 1.3–3.3 mm. 2n = 30.


Phenology: Flowering May–Jun(–Sep).
Habitat: Roadsides, open areas, edges of juniper-pine forests
Elevation: (1000–)1500–2500(–3500) m

Distribution

V21-1109-distribution-map.gif

Ariz., Calif., Idaho, Nev., Oreg., Utah.

Discussion

Some plants of Hymenoxys cooperi, mostly 10–40 cm with mostly 1–6 heads, have been called var. canescens.

Selected References

None.

Lower Taxa

None.
... more about "Hymenoxys cooperi"
not tailed +, rounded +  and obtuse +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
Mark W. Bierner +
(A. Gray) Cockerell +
decurrent +
Actinella cooperi +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Cooper’s rubberweed or bitterweed +
1.7 cm17 mm <br />0.017 m <br /> (2.15 cm21.5 mm <br />0.0215 m <br />) +
0.75 cm7.5 mm <br />0.0075 m <br /> (0.92 cm9.2 mm <br />0.0092 m <br />) +
1.02 cm10.2 mm <br />0.0102 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
0.27 cm2.7 mm <br />0.0027 m <br /> (0.48 cm4.8 mm <br />0.0048 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
hairy +  and glabrous +
obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
Ariz. +, Calif. +, Idaho +, Nev. +, Oreg. +  and Utah. +
(1000–)1500–2500(–3500) m +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Roadsides, open areas, edges of juniper-pine forests +
discoid +  and radiate +
in paniculiform to corymbiform arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.6 cm6 mm <br />0.006 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
subhemispheric;hemispheric +
1 cm10 mm <br />0.01 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
deltate +
dentate to pinnatifid or palmatifid +  and entire +
unequal +  and subequal +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.89 cm8.9 mm <br />0.0089 m <br />) +
2-carpellate +
persistent +
8 cm80 mm <br />0.08 m <br /> (13 cm130 mm <br />0.13 m <br />) +
3.5 cm35 mm <br />0.035 m <br /> (8 cm80 mm <br />0.08 m <br />) +
Flowering May–Jun(–Sep). +
28 +  and 50 +
Bull. Torrey Bot. Club +
bearing subulate enations +, hairy +  and bristly +
pitted +  and smooth +
conic;ovoid;conic;ovoid;hemispheric +
5 +  and 6 +
aristate +  and obovate +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.33 cm3.3 mm <br />0.0033 m <br />) +
exalbuminous +
subequal;unequal +
3 (?) +  and 15 (?) +
purple-red-tinted +
1 +  and 3 +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Hymenoxys cooperi var. canescens +
Hymenoxys cooperi +
Hymenoxys +
species +
urceolate +  and campanulate +
dilated +
toothed +  and entire +
80 cm800 mm <br />0.8 m <br /> (100 cm1,000 mm <br />1 m <br />) +
perennial +  and biennial +
obovate +  and oblanceolate +
0.41 cm4.1 mm <br />0.0041 m <br /> (0.68 cm6.8 mm <br />0.0068 m <br />) +
shrub +  and subshrub +