Erigeron modestus |
Erigeron vicinus |
|
---|---|---|
plains fleabane |
border fleabane, neighbor fleabane |
|
Habit | Perennials (sometimes flowering early and appearing annual or biennial), 8–40 cm; usually taprooted (taproots woody or lignescent, early season forms sometimes fibrous-rooted), caudices usually woody, sometimes branched. | Perennials, 10–30 cm; rhizomatous, fibrous-rooted, caudices with rhizomelike, relatively slender, lignescent, basal offsets 1–7 cm. |
Stems | (often multiple from bases; of previous year often persistent) ascending to spreading (proximally reddish in early season, sometimes proximally woody or lignescent), loosely strigose to villous (proximal hairs sometimes spreading), often sparsely glandular. |
ascending (branched at or below midstems), pilose on proximal 1/3 (hairs spreading-deflexed), loosely strigose distally, eglandular. |
Leaves | basal (often withering by late flowering) and cauline; blades oblanceolate to spatulate, 20–50(–100) × 3–7(–18) mm, gradually reduced distally, margins entire or with 1–2(–3) pairs of teeth, faces loosely strigose (hairs ascending), eglandular. |
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 | 3–4.5 × 6–9(–12) mm. |
4–5 × 7–10 mm. |
Ray florets | 24–65(–170); corollas white, often with abaxial midstripe, often drying lilac, 4–7(–11) mm, laminae not coiling or reflexing. |
60–95; corollas white, with lilac abaxial midstripe, 7–10 mm, laminae not coiling or reflexing. |
Disc corollas | 1.7–3.1 mm (throats indurate and slightly inflated). |
1.8–2.2 mm (throats slightly indurate or inflated). |
Phyllaries | in 2–3 series, sparsely to moderately hirsute, minutely glandular. |
in 2–3 series, sparsely hirsute, sparsely minutely glandular. |
Heads | 1(–3+, –50 in later season, branches at first from midstem or proximally, later more distal). |
1(–2) (branches from or proximal to midstem). |
Cypselae | 1.1–1.4 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of (5–)12–17 bristles. |
0.6–0.8 mm, 2-nerved, faces sparsely strigose; pappi: outer of scales, inner of 8–11 bristles. |
2n | = 27, 36. |
|
Erigeron modestus |
Erigeron vicinus |
|
Phenology | Flowering (Mar–)Apr–Jun(–Oct). | Flowering Jun–Aug. |
Habitat | Rocky or gravelly sites, sand, clay, limestone, granite, sometimes deep sand, often with oak or oak-juniper, shrubland | Rocky slopes and canyons, crevices |
Elevation | 200–1700(–2300) m (700–5600(–7500) ft) | 1600–2500 m (5200–8200 ft) |
Distribution |
AZ; KS; NM; OK; TX; Mexico (Coahuila, Chihuahua, Nuevo Leon)
|
TX; Mexico (Coahuila) |
Discussion | Erigeron modestus is a polyploid complex apparently incorporating genes from E. flagellaris, E. tracyi, elements of E divergens, and the Mexican E. pubescens Kunth; arbitrary identifications may be necessary. In most of its range in Texas, E. modestus is not sympatric with any of those other taxa. Forms flowering in early season (Mar–Apr) often have stems red at the bases, dentate basal leaves 30–60(–100) × 5–10(–18) mm, and single, relatively large heads (involucres 9–12 mm diam, ray florets 50–170, corollas 6.5–11 mm) on ebracteate peduncles 5–15 cm. Later season plants have nearly intricately branched stems with more numerous, much smaller, diffusely arranged heads. (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. 341. | FNA vol. 20, p. 342. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. lobatus var. warnockii, E. plateauensis, E. warnockii | |
Name authority | A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 68. (1849) | G. L. Nesom: Phytologia 69: 256. (1990) |
Web links |