Parthenium confertum

A. Gray

Proc. Amer. Acad. Arts 17: 216. 1882.

Synonyms: Parthenium confertum var. divaricatum Rollins Parthenium confertum var. lyratum (A. Gray) Rollins Parthenium confertum var. microcephalum Rollins
Treatment appears in FNA Volume 21. Treatment on page 22. Mentioned on page 21.

Biennials (sometimes flowering first-year or persisting), 10–30 (–60+) cm. Leaf-blades ovate or rounded-deltate to elliptic, 30–80 (–120+) × 10–20 (–40+) mm, usually ± pinnately or sub-bipinnately lobed, ultimate margins entire, faces strigillose, usually also with erect hairs 1–2 mm and glanddotted. Heads disciform or obscurely radiate, borne in open, ± paniculiform arrays. Peduncles 2–8 (–12+) mm. Phyllaries: outer 5 lanceovate to elliptic, 2.5–3+ mm, inner 5 ± orbiculate, 3–3.5 mm. Pistillate florets 5; corolla laminae 0 or ± coroniform, 0.1–0.5 mm. Disc-florets 20–30+. Cypselae ± obovoid, 2–3 mm; pappuslike enations 2, ± erect, deltate to ovate, 0.5–1 mm (sometimes a third, subulate spur near apex adaxially). 2n = 36, 68, 72.


Phenology: Flowering Mar–Oct.
Habitat: Sandy plains, openings in mesquite grasslands
Elevation: 20–2000 m

Distribution

V21-35-distribution-map.gif

Ariz., N.Mex., Tex., Mexico

Discussion

Selected References

None.

Lower Taxa

None.
... more about "Parthenium confertum"
72 +, 68 +  and 36 +
not tailed +, rounded +  and obtuse +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
John L. Strother +
A. Gray +
decurrent +
compound +  and simple +
lobed;spatulate;rounded-deltate;ovate;obovate;oblanceolate;lyrate;lanceolate +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
ochroleucous +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
villous +, strigillose +, hispidulous +, glabrous +  and warty +
scabrellous +  and tuberculate +
fertile +  and bisexual +
Ariz. +, N.Mex. +, Tex. +  and Mexico +
20–2000 m +
deltate +  and ovate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
strigillose +
winged +  and beaked +
dispersed +
Sandy plains, openings in mesquite grasslands +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
radiate +  and disciform +
in corymbiform , glomerate , paniculiform , racemiform or spiciform , arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
less scarious +  and membranous +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
hemispheric +
conspicuous +
oblong +  and reniform or orbiculate or more or less coroniform +
8 cm80 mm <br />0.08 m <br /> (12 cm120 mm <br />0.12 m <br />) +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
3 cm30 mm <br />0.03 m <br /> (8 cm80 mm <br />0.08 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
sessile +  and petiolate +
deltate +
dentate to pinnatifid or palmatifid +  and entire +
lanceovate +  and elliptic +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
herbaceous +  and scarious +
2-carpellate +
peripheral +
papillate +
fimbrillate;cuneate;flabelliform +
membranous +  and scarious +
persistent +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
Flowering Mar–Oct. +
unequal +  and subequal +
Proc. Amer. Acad. Arts +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Parthenium confertum var. divaricatum +, Parthenium confertum var. lyratum +  and Parthenium confertum var. microcephalum +
Parthenium confertum +
Parthenium +
species +
campanulate +  and cylindric +
toothed +  and entire +
30 cm300 mm <br />0.3 m <br /> (60 cm600 mm <br />0.6 m <br />) +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
shrub +  and subshrub +