Packera debilis

(Nuttall) W. A. Weber & Á. Löve

Phytologia 49: 46. 1981.

Common names: Weak groundsel
Endemic
Basionym: Senecio debilis Nuttall Trans. Amer. Philos. Soc., n. s. 7: 408. 1841
Synonyms: Senecio fedifolius Rydberg Senecio nephrophyllus Rydberg
Treatment appears in FNA Volume 20. Treatment on page 584. Mentioned on page 572, 574.
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Perennials, 20–50+ cm; ± fibrous-rooted (caudices weakly branched, relatively short). Stems 1 or 2–4, clustered, bases sparsely floccose-tomentose or glabrous, leaf-axils tomentose. Basal leaves (and proximal cauline, turgid) petiolate; blades elliptic to ovate or subreniform, 20–40+ × 15–30+ mm, bases cuneate to subcordate, margins subentire or crenate to crenate-dentate. Cauline leaves gradually reduced (sessile; pinnately lobed, sinuses deep, rounded, ultimate margins entire or subentire). Heads 6–20 in open or compact, corymbiform arrays. Peduncles ebracteate (or bractlets short), glabrous or sparsely hairy. Calyculi inconspicuous. Phyllaries 13 or 21, green (tips cyanic), 6–8+ mm, glabrous. Ray-florets 0. Disc-florets 45–65+; corolla-tubes 3–4 mm, limbs 2–3 mm. Cypselae 1–2 mm, glabrous; pappi 4.5–5.5 mm. 2n = 46.


Phenology: Flowering late Jun–mid Aug.
Habitat: Meadows, usually in alkaline soils
Elevation: 1700–3000 m

Discussion

Packera debilis is the most abundant of the rayless species of Packera in the southern Rocky Mountains. It is infrequently collected, nearly always from wet, alkaline meadows. The lobing and subsucculent nature of the leaves may be related to the substrate; that has not been tested experimentally.

Selected References

None.

Lower Taxa

None.
... more about "Packera debilis"
not tailed +, rounded +  and obtuse +
papillate +
truncate-penicillate +
scarious +
usually ovate +  and lance-linear +
corymbiform +, compact +  and open +
indeterminate +  and determinate +
Debra K. Trock +
(Nuttall) W. A. Weber & Á. Löve +
glabrous +  and floccose-tomentose +
cuneate +  and subcordate +
Senecio debilis +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
elliptic;ovate or subreniform +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
winged;nerved;ribbed +
inconspicuous +
Weak groundsel +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
pale-yellow +  and deep orange-red +
cylindric +
fertile +  and bisexual +
fertile +  and bisexual +
Colo. +, Idaho +, Mont. +  and Wyo. +
1700–3000 m +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Meadows, usually in alkaline soils +
discoid +  and radiate +
in compact or congested to open corymbiform cymiform or subumbelliform , , , arrays +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
campanulate;cylindric +
sessile +  and petiolate +
cauline +  and basal +
erect;recurved +
deltate +
dentate to pinnatifid +  and entire +
crenate +  and crenate-dentate +
2-carpellate +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
hairy +  and glabrous +
Flowering late Jun–mid Aug. +
linear +  and ensiform +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
bearing subulate enations +, hairy +  and bristly +
conic;usually flat;convex +
exalbuminous +
prostrate +  and ascending +
2 +  and 4 +
appendaged +  and truncate +
papillate +
Senecio fedifolius +  and Senecio nephrophyllus +
Packera debilis +
species +
campanulate +
serrate +  and denticulate +
20 cm200 mm <br />0.2 m <br /> (50 cm500 mm <br />0.5 m <br />) +
vine +, tree +, shrub +  and subshrub +
23 +, 22 +  and 20 +