Erigeron neomexicanus |
Erigeron vicinus |
|
---|---|---|
New Mexico fleabane |
border fleabane, neighbor fleabane |
|
Habit | Perennials, 20–70 cm; taprooted, caudices woody. | Perennials, 10–30 cm; rhizomatous, fibrous-rooted, caudices with rhizomelike, relatively slender, lignescent, basal offsets 1–7 cm. |
Stems | erect, moderately to densely strigose (hairs appressed to ascending, 0.1–0.8(–2) mm, sometimes spreading at bases or throughout), eglandular or glands minute, non-capitate. |
ascending (branched at or below midstems), pilose on proximal 1/3 (hairs spreading-deflexed), loosely strigose distally, eglandular. |
Leaves | basal (sometimes persistent) and cauline; blades oblanceolate, margins usually deeply pinnatifid (lobes in 2–5 pairs), sometimes dentate to entire, faces strigose, eglandular; basal 10–60 × 6–35 mm, cauline gradually reduced distally. |
basal (usually persistent) and cauline; basal blades lanceolate to oblanceolate or narrowly obovate, 10–30 × 3–10 mm; cauline little reduced distally, margins entire or with 1–2 pairs of teeth, loosely strigose (hairs ascending), eglandular. |
Involucres | 3.5–5 × 7–12 mm. |
4–5 × 7–10 mm. |
Ray florets | 70–150; corollas white, drying white, (2–)6–15 mm, laminae reflexing. |
60–95; corollas white, with lilac abaxial midstripe, 7–10 mm, laminae not coiling or reflexing. |
Disc corollas | 2.5–3.3 mm (throats somewhat white-indurate, not inflated). |
1.8–2.2 mm (throats slightly indurate or inflated). |
Phyllaries | in 3–4 series, strigose to hirsute (hairs arising mostly from midregion), usually minutely glandular, rarely eglandular. |
in 2–3 series, sparsely hirsute, sparsely minutely glandular. |
Heads | (1–)5–15(–30) in loosely corymbiform arrays. |
1(–2) (branches from or proximal to midstem). |
Cypselae | 1–1.3 mm, 2(–4)–nerved, faces sparsely strigose; pappi: (outer 0) inner (readily falling) of (8–)10–12 bristles. |
0.6–0.8 mm, 2-nerved, faces sparsely strigose; pappi: outer of scales, inner of 8–11 bristles. |
2n | = 18, 36. |
|
Erigeron neomexicanus |
Erigeron vicinus |
|
Phenology | Flowering (Jul–)Aug–Oct(–Dec). | Flowering Jun–Aug. |
Habitat | Open, rocky sites, from grasslands into oak or pine woodlands, often with madrono, juniper, or fir | Rocky slopes and canyons, crevices |
Elevation | (900–)1500–2700(–3000) m ((3000–)4900–8900(–9800) ft) | 1600–2500 m (5200–8200 ft) |
Distribution |
AZ; NM; Mexico (Chihuahua, Sonora)
|
TX; Mexico (Coahuila) |
Discussion | Relatively large, pinnatifid leaves are typical of Erigeron neomexicanus; plants with nearly entire leaves can be identified by the strongly perennial habit, white, reflexing rays, and 10–12 readily falling pappus bristles. Erigeron neomexicanus and E. oreophilus were treated by A. Cronquist (1947) as varieties of one species, and their morphologic similarity and the closeness of their geographic ranges support that hypothesis. But relatively few collections are found that could be regarded as intermediates, and both forms sometimes grow in proximity, apparently without a range of intermediates. In some Arizona mountain ranges, apparently only one or the other taxon occurs. Still, the possibility exists that these are populational segregants of a single species (see further comments in G. L. Nesom 1989d). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. In Texas, Erigeron vicinus grows in the Davis Mountains, Jeff Davis County. In its fibrous-rooted habit and perennial duration, finely strigose distal stems, and simple or branched stems with heads on relatively long peduncles, E. vicinus is similar to E. pubescens Kunth, a species occurring throughout much of the northern half of Mexico but apparently not reaching the United States, and to forms of E. modestus (especially with respect to the stems reddish and pilose at bases). Erigeron vicinus was originally described from the Sierra Madera del Carmen of Coahuila, where it was thought to be endemic. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 277. | FNA vol. 20, p. 342. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. delphiniifolius var. euneomexicanus, E. delphiniifolius subsp. neomexicanus | |
Name authority | A. Gray: Proc. Amer. Acad. Arts 19: 2. (1883) | G. L. Nesom: Phytologia 69: 256. (1990) |
Web links |