Difference between revisions of "Helenium microcephalum"

de Candolle in A. P. de Candolle and A. L. P. P. de Candolle

in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 667. 1836.

Common names: Smallhead sneezeweed
Treatment appears in FNA Volume 21. Treatment on page 433. Mentioned on page 428.
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(No difference)

Latest revision as of 22:36, 29 July 2020

Annuals, 25–120 cm. Stems 1 (2–10), branched distally, moderately to strongly winged, glabrous or sparsely hairy. Leaves glabrous or sparsely to moderately hairy (basal withered by flowering); proximal and mid-blades narrowly elliptic to narrowly oblongelliptic, usually serrate to undulate-serrate, sometimes deeply toothed or laciniate; distal blades narrowly elliptic to narrowly oblongelliptic, serrate to undulate-serrate. Heads 20–300+ per plant, in paniculiform arrays. Peduncles 1.8–8 cm, moderately hairy. Involucres globoid to usually ovoid, 4–12 × 4–12 mm. Phyllaries (connate proximally) moderately hairy. Ray-florets 7–13, pistillate, fertile; corollas usually yellow throughout, sometimes reddish proximally and yellow distally, 2.6–9.1 × 1.5–6.7 mm. Disc-florets 120–400+; corollas yellow to yellow-green proximally, brown to reddish-brown distally, 1.2–2.4 mm, lobes (4–) 5. Cypselae 0.7–1.4 mm, moderately hairy; pappi of usually 6 entire, non-aristate scales (0.2–) 0.3–0.7 mm.

Distribution

V21-1086-distribution-map.gif

Ariz., N.Mex., Okla., Tex., n Mexico

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Key

1 Peduncles 1–3.5 cm, projecting terminal heads barely beyond foliage; involucres 4–8 × 4–8 mm Helenium microcephalum var. microcephalum
1 Peduncles 1.5–8 cm, usually projecting terminal heads well beyond foliage; involucres 8–12 × 8–12 mm Helenium microcephalum var. oöclinium
... more about "Helenium microcephalum"
not tailed +, rounded +  and obtuse +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
paniculiform +
indeterminate +  and determinate +
Mark W. Bierner +
de Candolle in A. P. de Candolle and A. L. P. P. de Candolle +
decurrent +
compound +  and simple +
pinnatifid;lobed;spatulate;ovate;spatulate;ovate;oblong;oblanceolate;linear;lanceolate;elliptic +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Smallhead sneezeweed +
yellow +  and yellow-green proximally +
0.26 cm2.6 mm <br />0.0026 m <br /> (0.91 cm9.1 mm <br />0.0091 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.67 cm6.7 mm <br />0.0067 m <br />) +
4-5-angled +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
narrowly elliptic;narrowly oblongelliptic serrate +
Ariz. +, N.Mex. +, Okla. +, Tex. +  and n Mexico +
gland-dotted +
glabrous or +  and sparsely densely hairy +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
discoid +  and radiate +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (3.4 cm34 mm <br />0.034 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
sessile +  and petiolate +
glabrous or +  and sparsely moderately hairy +
deltate +
dentate to pinnatifid or palmatifid +  and entire +
connate +  and distinct +
ovate +, oblong +, oblanceolate +, linear +, lanceolate +  and elliptic +
unequal +  and subequal +
2-carpellate +
persistent +
1.8 cm18 mm <br />0.018 m <br /> (8 cm80 mm <br />0.08 m <br />) +
9 +  and 34 +
in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. +
bearing subulate enations +, hairy +  and bristly +
ovoid;hemispheric;ovoid;hemispheric;globose;conic +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
5 +  and 12 +
non-aristate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
exalbuminous +
winged +  and branched +
2 (?) +  and 10 (?) +
hairy +  and glabrous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Compositae +
Helenium microcephalum +
Helenium +
species +
urceolate +  and campanulate +
dilated +
toothed +  and entire +
25 cm250 mm <br />0.25 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
shrub +  and subshrub +