Hymenoxys helenioides

(Rydberg) Cockerell

Bull. Torrey Bot. Club 31: 481. 1904.

Common names: Intermountain rubberweed or bitterweed
Endemic
Basionym: Picradenia helenioides Rydberg Bull. Torrey Bot. Club 28: 21. 1901
Treatment appears in FNA Volume 21. Treatment on page 442. Mentioned on page 435, 437.

Perennials, 20–50 cm (polycarpic; usually with moderately branched, woody caudices). Stems 1–5 (–10+), green throughout or lightly purple-red-tinted proximally, branched distally, ± hairy. Leaves: blades simple or lobed (lobes 3), glabrous or sparsely hairy, glanddotted (basal leaf-bases sparsely, if at all, long-villous-woolly); mid leaves usually lobed (lobes 3, terminal lobes 2–5.5 mm wide), sometimes simple. Heads 5–50+ per plant, in paniculiform to corymbiform arrays. Peduncles (2.5–) 4–7.5 cm, ± hairy. Involucres subhemispheric to hemispheric, 9–12 × 12–18 mm. Phyllaries in 2 series, unequal; outer 10–15, basally connate 1/4–1/3 their lengths (weakly keeled), lanceolate, 7.5–11 mm, apices acuminate; inner 13 (–17), obovate, 5–8 mm, apices acuminate to mucronate. Ray-florets 10–16; corollas yellow to yellow-orange, 17–31 × 5–11 mm. Disc-florets 50–150+; corollas 3.5–5.5 mm. Cypselae narrowly obpyramidal, 2.5–3.5 mm; pappi of 5–7 obovate to lanceolate, aristate scales 2.5–4 mm. 2n = 30.


Phenology: Flowering Jun–Aug.
Habitat: Roadsides, open areas, edges of forests
Elevation: 2200–3000 m

Discussion

Selected References

None.

Lower Taxa

None.
... more about "Hymenoxys helenioides"
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 +
(Rydberg) Cockerell +
decurrent +
Picradenia helenioides +
hairy +  and glabrous +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Intermountain rubberweed or bitterweed +
yellow +  and yellow-orange +
1.7 cm17 mm <br />0.017 m <br /> (3.1 cm31 mm <br />0.031 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
hairy +  and glabrous +
obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
Ariz. +, Colo. +  and Utah. +
2200–3000 m +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Roadsides, open areas, edges of 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 />) +
0.9 cm9 mm <br />0.009 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
subhemispheric;hemispheric +
1.2 cm12 mm <br />0.012 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
deltate +
dentate to pinnatifid or palmatifid +  and entire +
unequal +  and subequal +
0.75 cm7.5 mm <br />0.0075 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
2-carpellate +
persistent +
5 +  and 7 +
obovate +  and lanceolate +
2.5 cm25 mm <br />0.025 m <br /> (4 cm40 mm <br />0.04 m <br />) +
4 cm40 mm <br />0.04 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
Flowering Jun–Aug. +
28 +  and 50 +
Bull. Torrey Bot. Club +
bearing subulate enations +, hairy +  and bristly +
pitted +  and smooth +
conic;ovoid;conic;ovoid;hemispheric +
2 +  and 11 +
aristate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
exalbuminous +
subequal;unequal +
5 (?) +  and 10 (?) +
green throughout or lightly purple-red-tinted +
1 +  and 5 +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Dugaldia +  and Plummera +
Hymenoxys helenioides +
Hymenoxys +
species +
urceolate +  and campanulate +
dilated +
toothed +  and entire +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
shrub +  and subshrub +