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170. Erigeron strigosus Muhlenberg ex Willdenow, Sp. Pl. 3: 1956. 1803.
Common eastern fleabane, vergerette rude
Erigeron annuus (Linnaeus) Persoon subsp. strigosus (Muhlenberg ex Willdenow) Wagenitz
Annuals, biennials, or short-lived perennials, 30–70 cm; fibrous-rooted, caudices simple, sometimes lignescent, sometimes producing rhizomes that bear leaf tufts at upturned ends. Stems erect or ascending, sparsely to moderately strigose to strigillose or hirsuto-strigillose (hairs usually ascending, rarely spreading, 0.1–1.2 mm), eglandular. Leaves basal (usually persistent through flowering) and cauline; basal blades spatulate to broadly or narrowly oblanceolate to linear, (10–)30–150(–170) × 5–15(–21) mm, cauline usually gradually reduced distally, continuing to near heads, margins entire or shallowly to deeply serrate or crenate, faces glabrous or glabrate to sparsely strigose or strigoso-hirsute, eglandular. Heads 10–200+ in loosely corymbiform to paniculiform-corymbiform arrays (on distal branches). Involucres (2–)3–4 × 5–12 mm. Phyllaries in 2–4 series, glabrous, strigose, or sparsely hirsute, sometimes minutely glandular. Ray florets 50–100; corollas white, less commonly pinkish or bluish, 4–6 mm, laminae coiling. Disc corollas 1.5–2.5 mm (throats sometimes slightly indurate and inflated). Cypselae (0.5–)0.9–1.2 mm, 2-nerved, faces sparsely strigose; pappi: outer crowns of setae or scales, inner 0 (rays) or of 8–15 bristles (disc).
Varieties 4 (4 in the flora): North America; introduced in Europe, Pacific Islands (Hawaii).
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1 |
Phyllary hairs flattened, 0.5–1.2 mm; stem hairs appressed to spreading, 0.5–1 mm |
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170c Erigeron strigosus var. septentrionalis |
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Phyllary hairs terete, mostly 0.1–0.5 mm; stem hairs appressed to ascending, 0.1–0.4(–0.8) mm |
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(2) |
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2 (1) |
Annual or rarely biennial, without rhizomes; various habitats, often ruderal |
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170d Erigeron strigosus var. strigosus |
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Plants usually perennial (sometimes killed prematurely by severe drought), with rhizomes that bear overwintering leaf tufts at upturned ends; shallow soils over calcareous rock |
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(3) |
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3 (2) |
Basal leaves linear to linear-oblanceolate, 1–3.5(–6) mm wide; cauline leaf faces sparsely to moderately strigillose |
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170b Erigeron strigosus var. dolomiticola |
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Basal leaves oblanceolate to narrowly obovate or spatulate, (3.2–)3.8–15(–21) mm wide; cauline leaf faces glabrous, margins and midveins ciliate |
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170a Erigeron strigosus var. calcicola |
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Treatments in Other Floras @ www.efloras.org
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