Erigeron divergens |
Erigeron parryi |
|
---|---|---|
branching fleabane diffuse daisy, diffuse daisy, diffuse fleabane, spreading fleabane |
Parry's fleabane |
|
Habit | Annuals or short-lived perennials, (7–)12–40(–70) cm; taprooted, caudices simple if perennial. | Perennials, 1.5–5(–15) cm; taprooted, caudices multicipital or with relatively short, thick branches. |
Stems | (single or multiple from bases) erect to ascending, densely and evenly puberulous-hirsutulous (hairs spreading to spreading-descending or -ascending, often crinkly, bases not thickened), minutely glandular at least distally, usually throughout. |
erect, usually hirsute, rarely loosely strigoso-villous, eglandular. |
Leaves | basal (usually deciduous) and cauline; basal blades obovate-spatulate, 10–70 × 4–-14 mm; cauline gradually reduced distally, margins entire or with 2–3 pairs of teeth or lobes, faces hirsute to loosely strigoso-hirsute, sometimes sparsely glandular. |
basal (persistent) and cauline; basal blades linear-oblanceolate, 10–25(–50) × 0.8–2 mm; cauline on proximal 1/2–2/3 of stems, gradually reduced distally, margins entire, eciliate (apices rounded to obtuse), faces equally, densely loosely strigose to hirsuto-strigose, eglandular. |
Involucres | 3–4 × (5–)7–11 mm. |
4–7 × 7–10 mm. |
Ray florets | 75–150; corollas white, drying lilac, without abaxial midstripe, (2–)4–9.5 mm, laminae not coiling or reflexing (remaining relatively straight). |
20–40; corollas white to pink or bluish, 6–8 mm, laminae not coiling or reflexing. |
Disc corollas | 1.8–2.3 mm (throats indurate and slightly inflated). |
2.4–3.5 mm. |
Phyllaries | in 3–4 series, hirsute, minutely glandular. |
in (2–)3 series (subequal), sparsely to densely villoso-strigose (basal cross walls sometimes purple), sparsely minutely glandular. |
Heads | (in early season, 1–)5–100+ (buds nodding). |
1(–3, rarely). |
Cypselae | 0.9–1.2 mm, 2-nerved (nerves whitish), faces sparsely strigose; pappi: outer of setae or scales, inner of 6–9(–12) bristles. |
2–2.3 mm, 2-nerved, faces densely strigose; pappi: outer of setae or scales, inner of 12–15 (readily falling) bristles. |
2n | = 18, 27, 36. |
|
Erigeron divergens |
Erigeron parryi |
|
Phenology | Flowering (Feb–)Apr–Oct. | Flowering Jun–Aug. |
Habitat | Gravelly or sandy flats, riverbanks, meadows, disturbed sites, desert scrubland to grasslands, saltbush, blackbrush, sagebrush, pinyon-juniper, juniper-oak, oak, and ponderosa pine woodlands | Open, rocky (limestone) slopes and ridgecrests, sagebrush |
Elevation | 60–2000(–2700) m (200–6600(–8900) ft) | 1300–2200 m (4300–7200 ft) |
Distribution |
AZ; CA; CO; ID; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; AB; BC; Mexico (Baja California, Chihuahua, Coahuila, Durango, Sonora, and southward)
|
MT; WY |
Discussion | Polyploidy and agamospermy apparently are common in Erigeron divergens and contribute to the variability and, probably to some extent, the polymorphism characteristic of this species. Diploids appear to be scattered through the range of the species, at least in its southern part. The form of Erigeron divergens with persistent, deeply pinnatifid basal leaves with relatively long petioles and tendency toward perenniality (woody taproots) has been named E. accedens [occurs at 200–1000(–1200) m and flowers Feb–Apr(–May)]. Such plants have sometimes been identified as E. lobatus, and it is possible that they may have originated as hybrids with it; in most ways they are similar to E. divergens and apparently intergrade with it. The E. accedens form occurs in California, Arizona, New Mexico, southwest Texas, Baja California, northern Sonora, Durango, and Chihuahua, apparently sympatrically with more typical E. divergens, suggesting that the former is stabilized and self-reproductive (probably agamospermic). Available chromosome counts are triploid. Rare plants (e.g., E. incomptus) may have filiform rays barely extending past the involucre. Another common form of Erigeron divergens in the broad sense (mostly in Chihuahua, also southern Texas, New Mexico, and Arizona) has bowl-shaped plants with decumbent stems, a discrete taproot, persistent, lobed basal leaves, and solitary heads topping usually simple stems, and usually is early-season in phenology. Further comments related to variation in E. divergens are found under 163. Erigeron multiceps. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Erigeron parryi mostly has been included within the concept of E. ochroleucus, but two studies (P. Lesica 2005; G. L. Nesom 2004e) independently have confirmed its reality as an endemic of southwestern Montana and adjacent Wyoming. Leaves of E. parryi are equally hairy (usually hirsuto-strigose) on both faces, contrasted with the reduced vestiture (loosely strigose) only on adaxial leaf faces of E. ochroleucus, and the involucral vestiture is of hairs often with purplish cross walls. Also, E. parryi produces branched caudices and smaller heads with fewer rays. Lesica also noted as distinctive the caudex branches thickened by the presence of old leaf bases proximal to the current leaves. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 339. | FNA vol. 20, p. 293. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. divaricatus, E. accedens, E. incomptus, E. solisaltator | |
Name authority | Torrey & A. Gray: Fl. N. Amer. 2: 175. (1841) | Canby & Rose: Bot. Gaz. 15: 65. (1890) |
Web links |