Parthenium alpinum

(Nuttall) Torrey & A. Gray

Fl. N. Amer. 2: 285. 1842.

Endemic
Basionym: Bolophyta alpina Nuttall Trans. Amer. Philos. Soc., n. s. 7: 348. 1840
Synonyms: Parthenium tetraneuris Barneby Parthenium alpinum var. tetraneuris (Barneby) Rollins
Treatment appears in FNA Volume 21. Treatment on page 21. Mentioned on page 9, 20.

Perennials, 1–2 cm (underground caudices 2–5+ cm, branched; plants cespitose or forming mats). Leaf-blades oblanceolate to spatulate, 6–18 (–35) × 1–3 (–4+) mm, margins entire, faces strigilloso-sericeous (gray) and obscurely glanddotted. Heads ± disciform, borne singly. Peduncles 0–5 (–30) mm. Phyllaries: outer 5–8 ± linear, 4 mm, inner 5–8 ± orbiculate, 4–5 mm. Pistillate florets 5–8; corolla laminae 0 (tubes ± compressed, obscurely 2–4-lobed). Disc-florets 18–28+. Cypselae oblanceoloid, 4 mm (narrowly winged); pappuslike enations 2, erect to spreading, ± subulate, 0.5–1 mm (a third, ± subulate element sometimes at apex of adaxial face). 2n = 36.


Phenology: Flowering May–Jul.
Habitat: Shale and calcareous outcrops, red clays
Elevation: 1300–1700 m

Discussion

Parthenium alpinum is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.
... more about "Parthenium alpinum"
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 +
(Nuttall) Torrey & A. Gray +
decurrent +
Bolophyta alpina +
compound +  and simple +
lobed;spatulate;rounded-deltate;ovate;obovate;oblanceolate;lyrate;lanceolate +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
ochroleucous +
villous +, strigillose +, hispidulous +, glabrous +  and warty +
scabrellous +  and tuberculate +
oblanceoloid +
fertile +  and bisexual +
Colo. +, N.Mex. +  and Wyo. +
1300–1700 m +
subulate +  and pappuslike +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
strigilloso-sericeous +
winged +  and beaked +
dispersed +
Shale and calcareous outcrops, red clays +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 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 +
1.8 cm18 mm <br />0.018 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
sessile +  and petiolate +
deltate +
4 cm40 mm <br />0.04 m <br /> (?) +
herbaceous +  and scarious +
2-carpellate +
peripheral +
papillate +
fimbrillate;cuneate;flabelliform +
membranous +  and scarious +
persistent +
0.5 cm5 mm <br />0.005 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Flowering May–Jul. +
unequal +  and subequal +
Fl. N. Amer. +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Parthenium tetraneuris +  and Parthenium alpinum var. tetraneuris +
Parthenium alpinum +
Parthenium +
species +
campanulate +  and cylindric +
toothed +  and entire +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
shrub +  and subshrub +