Erigeron porsildii

G. L. Nesom & D. F. Murray

Sida 21: 44. 2004.

Common names: Porsild’s Arctic fleabane
Endemic
Basionym: Erigeron grandiflorus subsp. arcticus A. E. Porsild Publ. Bot. (Ottawa) 4: 67. 1975,
Treatment appears in FNA Volume 20. Treatment on page 324. Mentioned on page 267, 325.

Perennials, (2–) 10–20 (–25) cm; rhizomatous, fibrous-rooted, rhizomes horizontal or erect, sometimes branched, relatively short, sometimes resembling taproots. Stems erect, sparsely to moderately villous (hairs 0.5–1.6 mm), usually stipitate-glandular (hairs 0.05–0.4 mm). Leaves basal (persistent) and cauline; basal blades oblong-oblanceolate to narrowly obovate, 30–120 × (3–) 5–14 mm, margins entire (apices acute), faces densely hirsute to coarsely villous, sparsely stipitate-glandular to minutely glandular; cauline blades oblong-lanceolate to lanceolate, gradually reduced distally or nearly equal-sized (bases often subclasping). Heads 1. Involucres 6–10 × 12–20 mm. Phyllaries in ca. 2 series (purple at least at tips, narrowly lanceolate, equal, apically acuminate), densely hirsute, hirsuto-villous, or villous (hairs whitish, cross-walls not colored), sparsely stipitate-glandular to minutely glandular. Ray-florets 65–110; corollas white to lavender or blue, 13–17 mm (1.2–1.7 mm wide), laminae weakly coiling. Disc corollas 3.8–4.5 mm. Cypselae 2–2.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of relatively long setae or scales, inner of 14–20 (–25) bristles. 2n = 36.


Phenology: Flowering (Jun–)Jul–Aug(–Sep).
Habitat: Cliffs and talus (often calcareous) slopes, shaley gravel, grassy ravines, dry tundra
Elevation: 600–2100 m

Discussion

Erigeron hultenii S. A. Spongberg was noted to be “closely allied to the polymorphic arctic-alpine species E. grandiflorus W. J. Hooker” (S. A. Spongberg 1973, p. 116) and to have a “close morphologic resemblance to some plants of E. grandiflorus from Alaska” [E. porsildii in the present sense] (p. 119). Plants corresponding to E. hultenii have not been recollected, and that taxon does not fit with any other known Alaskan species. Contrasts with E. porsildii exclude it from that species. Erigeron hultenii is not recognized formally herein.

Selected References

None.

Lower Taxa

None.
... more about "Erigeron porsildii"
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
paniculiform +, corymbiform +  and loose +
indeterminate +  and determinate +
Guy L. Nesom +
G. L. Nesom & D. F. Murray +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
3 cm30 mm <br />0.03 m <br /> (12 cm120 mm <br />0.12 m <br />) +
oblong-oblanceolate +  and narrowly obovate +
0.5 cm5 mm <br />0.005 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
decurrent +
Erigeron grandiflorus subsp. arcticus +
linear;lanceolate oblanceolate or spatulate +
rugulose +  and muricate +
oblong-lanceolate +  and lanceolate +
equal-sized +, or +  and reduced +
Porsild’s Arctic fleabane +
not 2-lipped +  and actinomorphic +
white +  and lavender or blue +
1.3 cm13 mm <br />0.013 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
subterete +, oblong +  and oblong-obovoid compressed +
fertile +  and bisexual +
0.38 cm3.8 mm <br />0.0038 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
fertile +  and bisexual +
N.W.T. +, Yukon +  and Alaska. +
600–2100 m +
strigose +, densely hirsute +  and coarsely villous sparsely stipitate-glandular +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Cliffs and talus (often calcareous) slopes, shaley gravel, grassy ravines, dry tundra +
disciform +  and discoid +
in loose , corymbiform or paniculiform arrays +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
turbinate;hemispheric +
1.2 cm12 mm <br />0.012 m <br /> (2 cm20 mm <br />0.02 m <br />) +
petiolate +  and sessile +
cauline +  and basal +
erect;spreading +
deltate +
not +  and scarious +
2-carpellate +
Flowering (Jun–)Jul–Aug(–Sep). +
3-nerved +  and 1-nerved +
villous sparsely stipitate-glandular +  and minutely glandular +
narrowly elliptic +  and linear-lanceolate +
bearing subulate enations +, hairy +  and bristly +
erect +  and horizontal +
exalbuminous +
branched +  and simple +
prostrate +  and decumbent +
stipitate-glandular +  and villous +
appendaged +  and truncate +
papillate +  and smooth +
Achaetogeron +  and Trimorpha +
Erigeron porsildii +
Erigeron +
species +
inflated +  and tubular +
fibrous-rooted +  and rhizomatous +
20 cm200 mm <br />0.2 m <br /> (25 cm250 mm <br />0.25 m <br />) +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
tree +, shrub +  and subshrub +