Senecio integerrimus

Nuttall

Gen. N. Amer. Pl. 2: 165. 1818.

IllustratedEndemic
Treatment appears in FNA Volume 20. Treatment on page 556. Mentioned on page 547, 554.

Perennials (possibly biennials), (10–) 20–70 cm (caudices buttonlike, roots fleshy-fibrous). Herbage arachnose, loosely tomentose, or villous (hairs crisped, jointed), glabrescent. Stems single. Leaves progressively reduced distally; ± petiolate; blades elliptic, lanceolate, linear, oblanceolate, rounded-deltate, or suborbiculate, 6–25 × 1–6 cm, bases ± tapered or truncate to cordate, margins entire or ± dentate (distal leaves sessile, bractlike). Heads 6–20 (–40+) in corymbiform arrays (peduncle of terminal head often shorter than others). Calyculi of 1–5+ linear to filiform bractlets (seldom more than 2 mm). Phyllaries usually ± 13 or ± 21, rarely ± 8, (4–) 5–12 (–15) mm, tips usually black, sometimes green. Ray-florets usually ± 8 or ± 13, sometimes 0; corolla laminae 6–15 (–20) mm (usually yellow, ochroleucous to white in one variety). Cypselae usually glabrous, sometimes hirtellous (mostly on angles). 2n = 40, 80.

Distribution

V20-1230-distribution-map.gif

Alta., B.C., Man., Sask., Calif., Colo., Idaho, Iowa, Kans., Minn., Mont., N.Dak., N.Mex., Nebr., Nev., Oreg., S.Dak., Utah, Wash., Wyo.

Discussion

Varieties 5 (5 in the flora).

The varieties of Senecio integerrimus are distinguished by morphology and geography.

Selected References

None.

Key

1 Basal leaves with distinct petioles, blades usually ovate to rounded-deltate, sometimes obovate to oblanceolate; ray corollas white or ochroleucous Senecio integerrimus var. ochroleucus
1 Basal leaves with or without distinct petioles, blades elliptic, lanceolate, oblanceolate, rounded-deltate, sublinear, or suborbiculate; ray corollas yellow (or rays 0) > 2
2 Herbage glabrous or glabrate at flowering (except in leaf axils and among heads); phyllaries linear-subulate, tips usually green, minutely (if at all) black Senecio integerrimus var. integerrimus
2 Herbage usually arachnose, tomentose, or villous at flowering; phyllaries lanceolate to linear-subulate, tips black (if minutely so, then narrowly lanceolate and broader than subulate) > 3
3 Basal and proximal leaves oblong or lanceolate to sublinear; heads 3–6(–16+); phyllaries 10–15+ mm Senecio integerrimus var. scribneri
3 Basal and proximal leaves mostly elliptic to oblanceolate, sometimes elliptic or rounded-deltate to suborbiculate; heads usually 6–15(–30+; if fewer than 6, leaves lanceolate or broader); phyllaries 5–12 mm. > 4
4 Plants copiously arachnose, tomentose, or villous at flowering; phyllaries linear-subulate, 8–12 mm, tips minutely, if at all, blackened Senecio integerrimus var. major
4 Plants copiously to sparsely arachnose, tomentose, or villous at flowering; phyllaries mostly lanceolate (seldom as narrow as linear-subulate), 5–10 mm, tips black Senecio integerrimus var. exaltatus
... more about "Senecio integerrimus"
not tailed +, rounded +  and obtuse +
papillate +
scarious +
usually ovate +  and lance-linear +
indeterminate +  and determinate +
Theodore M. Barkley† +
Nuttall +
less tapered or truncate +  and cordate +
6 cm60 mm <br />0.06 m <br /> (25 cm250 mm <br />0.25 m <br />) +
suborbiculate;rounded-deltate;suborbiculate;rounded-deltate;oblanceolate;linear;lanceolate;elliptic +
1cm;6cm +
winged;nerved;ribbed +
linear;filiform +
barbellulate +  and smooth +
white +  and stramineous +
purplish +, reddish +, white +, ochroleucous +, yellow +  and white rarely reddish +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
hirtellous +  and glabrous +
angled +, 5-ribbed +, prismatic +  and cylindric +
fertile +  and bisexual +
fertile +  and bisexual +
Alta. +, B.C. +, Man. +, Sask. +, Calif. +, Colo. +, Idaho +, Iowa +, Kans. +, Minn. +, Mont. +, N.Dak. +, N.Mex. +, Nebr. +, Nev. +, Oreg. +, S.Dak. +, Utah +, Wash. +  and Wyo. +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
discoid +  and radiate +
indeterminate +
heterogamous +  and homogamous +
glabrescent +, villous +, tomentose +  and arachnose +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
turbinate;campanulate +
cauline +  and basal +
reduced +
erect;recurved +
deltate +
dentate +  and entire +
2-carpellate +
persistent +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
mostly oblong +  and lanceolate or linear +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
Gen. N. Amer. Pl. +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
exalbuminous +
Illustrated +  and Endemic +
appendaged +  and truncate +
papillate +
Compositae +
Senecio integerrimus +
species +
campanulate +
green +  and black +
denticulate +  and serrate or toothed +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
20 cm200 mm <br />0.2 m <br /> (70 cm700 mm <br />0.7 m <br />) +
shrub +  and subshrub +