Agoseris retrorsa

(Bentham) Greene

Pittonia 2: 178. 1891.

Common names: Spearleaf agoseris
Basionym: Macrorhynchus retrorsus Bentham Pl. Hartw., 320. 1849
Synonyms: Macrorhynchus angustifolius Kellogg
Treatment appears in FNA Volume 19. Treatment on page 330. Mentioned on page 325, 329, 331, 332.

Stems 0. Leaves erect to ascending; petioles often purplish; blades linear to linear-elliptic, (7–) 10–30 (–36) cm, margins usually lobed to pinnatifid, rarely toothed or entire, lobes (4–) 7–9 (–11) pairs, linear to lanceolate, mostly retrorse, sometimes spreading, lobules often present, faces sparsely villous to tomentose. Peduncles elongating after flowering, 15–65 (–94) cm in fruit, ± glabrate, or apically villous to tomentose, eglandular. Involucres cylindric to obconic or campanulate, 4–6 cm in fruit. Phyllaries in 3–5 series, medially rosy purple or all green, lacking darker spots or midstripes, margins ciliate to tomentose, faces glabrous or villous, eglandular; outer erect to spreading, adaxially glabrous or tomentose; inner erect, often precociously elongating and much surpassing outer. Receptacles epaleate. Florets 10–100; corollas yellow, tubes 8–20 mm, ligules 6–15 × 1.5–2.5 mm; anthers 2–5 mm. Cypselae (15–) 20–31 mm, bodies narrowly obconic, 5–7 mm, beaks (10–) 15–25 mm, lengths mostly 3–4 times bodies; ribs strongly ridged, straight, often minutely cinereous-pannose; pappus bristles in 4–6 series, (11–) 15–20 mm. 2n = 18.


Phenology: Flowering Apr–Aug.
Habitat: Mesic to dry habitats in scrub-lands, chaparral, steppe, and open oak or pine woodlands
Elevation: 400–2300 m

Distribution

V19-505-distribution-map.gif

Ariz., Calif., Nev., Oreg., Utah, Wash., Mexico (Baja California)

Discussion

Agoseris retrorsa appears to be most closely related to A. grandiflora. It superficially resembles A. parviflora and the two are sometimes confused. Agoseris retrorsa occurs primarily west of the Sierra Nevada; A. parviflora occurs primarily east of the same range. Cypsela characteristics will quickly separate them. Putative hybrids between A. retrorsa and A. grandiflora, A. hirsuta, and A. parviflora have been identified.

Selected References

None.

Lower Taxa

None.

"fine" is not a number."elongating" is not a number.

... more about "Agoseris retrorsa"
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
scarious +
ovate +  and lanceolate +
corymbiform +  and paniculiform +
indeterminate +  and determinate +
Gary I. Baird +
(Bentham) Greene +
decurrent +
Macrorhynchus retrorsus +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
3-4 times bodies +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
compound +  and simple +
tuberculate +, rugose +, muricate +  and smooth +
obconic +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
filiform +
2 (?) +  and 6 (?) +
acute +, linear-lanceolate +  and cuneate-oblanceolate +
Spearleaf agoseris +
pistillate +  and staminate +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
papillate +
tapered +, beaked +, flattened +, obcompressed +, compressed +, prismatic +, fusiform +, ellipsoid +, columnar +  and clavate +
Ariz. +, Calif. +, Nev. +, Oreg. +, Utah +, Wash. +  and Mexico (Baja California) +
400–2300 m +
villous +, glabrous +, sparsely villous +  and tomentose +
winged +  and beaked +
dispersed +
Mesic to dry habitats in scrub-lands, chaparral, steppe, and open oak or pine woodlands +
indeterminate +
each +  and sessile +
pistillate +  and staminate +
cylindric;obconic or campanulate +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1.5mm;2.5mm +
spreading;retrorse +
linear +  and lanceolate +
ciliate +  and tomentose +
usually lobed +  and pinnatifid rarely toothed or entire +
erect +  and spreading +
tomentose +  and glabrous +
2-carpellate +
pistillate +  and staminate +
1.1 cm11 mm <br />0.011 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
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 /> (0.7 cm7 mm <br />0.007 m <br />) +
less glabrate or apically villous +  and tomentose +
Flowering Apr–Aug. +
connate +  and distinct +
subequal +  and unequal +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
straight +
cinereous-pannose +
ridged +
exalbuminous +
prostrate +  and ascending +
appendaged +  and truncate +
papillate +
Macrorhynchus angustifolius +
Agoseris retrorsa +
Agoseris +
species +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
perennial +, biennial +  and annual +