Helenium microcephalum var. microcephalum

Treatment appears in FNA Volume 21. Treatment on page 434.

Plants 30–120 cm. Leaves: proximal and mid-blades serrate to undulate-serrate, glabrous or sparsely hairy; distal blades glabrous or sparsely hairy. Heads 20–150 (–300+) per plant. Peduncles 1–3.5 cm, projecting terminal heads barely beyond foliage. Involucres 4–8 × 4–8 mm. Ray-florets 7–13; corollas yellow, 2.6–4.8 × 1.6–3.9 mm. Disc-florets 120–300+; corollas 1.2–1.6 mm, lobes (4–) 5. Pappi (0.2–) 0.3–0.4 (–0.5) mm. 2n = 26.


Phenology: Flowering (Feb–)Jun–Jul(–Nov).
Habitat: Sandy or clay soils, ditches, washes, around ponds and lakes, along streams
Elevation: 0–1500 m

Distribution

V21-1087-distribution-map.gif

Ariz., N.Mex., Okla., Tex., Mexico (Coahuila), Mexico (Nuevo León), Mexico (and Tamaulipas)

Discussion

Selected References

None.

Lower Taxa

None.
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 +
0.26 cm2.6 mm <br />0.0026 m <br /> (0.48 cm4.8 mm <br />0.0048 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
0.16 cm1.6 mm <br />0.0016 m <br /> (0.39 cm3.9 mm <br />0.0039 m <br />) +
4-5-angled +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
hairy +  and glabrous +
narrowly elliptic;narrowly oblongelliptic serrate +
Ariz. +, N.Mex. +, Okla. +, Tex. +, Mexico (Coahuila) +, Mexico (Nuevo León) +  and Mexico (and Tamaulipas) +
0–1500 m +
gland-dotted +
glabrous or +  and sparsely densely hairy +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Sandy or clay soils, ditches, washes, around ponds and lakes, along streams +
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 /> (0.8 cm8 mm <br />0.008 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 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 +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
persistent +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
Flowering (Feb–)Jun–Jul(–Nov). +
9 +  and 34 +
hairy +  and glabrous +
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 var. microcephalum +
Helenium microcephalum +
variety +
urceolate +  and campanulate +
dilated +
toothed +  and entire +
25 cm250 mm <br />0.25 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +