Eupatorium leucolepis |
Eupatorium resinosum |
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justiceweed, white-bract thoroughwort |
pine barren thoroughwort |
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Habit | Perennials, 40–100+ cm. | Perennials, 40–100+ cm. | ||||
Stems | (from short caudices or stout rhizomes) single, sparsely branched distally, puberulent throughout (more densely distally and among heads). |
(from short rhizomes) single, branched distally (among heads), puberulent throughout. |
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Leaves | usually opposite (distal sometimes alternate, ascending to vertical); sessile; blades pinnately nerved, lance-oblong to linear-oblong, 20–60 × 4–10(–15) mm, bases rounded to cuneate (not connate-perfoliate), margins entire or serrate, apices acute, faces villous (abaxial), scabrous (adaxial), gland-dotted. |
usually opposite (distal sometimes alternate); sessile; blades pinnately nerved, narrowly elliptic, 40–100+ × 5–20 mm, bases cuneate (not perfoliate), margins serrate, apices acute to acuminate, faces puberulent, gland-dotted. |
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Florets | 5; corollas 3–3.5 mm. |
9–14; corollas 3–3.5 mm. |
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Phyllaries | 8–10 in 2–3 series, narrowly elliptic, 2.5–8 × 0.8–1.2 mm, acuminate to attenuate, mucronate, abaxial faces puberulent, gland-dotted. |
10–12 in 2–3 series, elliptic to oblong, 1.5–4 × 0.8–1 mm, apices broadly acute to acute, abaxial faces puberulent, gland-dotted. |
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Heads | in corymbiform arrays. |
in corymbiform arrays. |
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Cypselae | 2–3 mm; pappi of 30–40 bristles 4.5–5 mm. |
2–3 mm; pappi of 20–30 bristles 3–3.5 mm. |
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2n | = 20. |
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Eupatorium leucolepis |
Eupatorium resinosum |
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Phenology | Flowering Aug–Sep. | |||||
Habitat | Moist, low ground, pocosins, bogs, cutover woodlands, pine barrens, acid soils | |||||
Elevation | 20–100+ m (100–300+ ft) | |||||
Distribution |
AL; DE; FL; GA; LA; MA; MD; MS; NC; NJ; NY; PA; RI; SC; TN; TX; VA
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NC; NJ; SC |
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Discussion | Varieties 2 (2 in the flora). Eupatorium leucolepis is distinct morphologically by its acuminate to attenuate phyllaries, linear and usually plicate leaves, and phyllotaxy that is almost always strictly opposite to the arrays, with well-separated nodes. Eupatorium leucolepis has recently been shown to include two distinct species, an unnamed diploid that is endemic to Carolina Bay habitats and a series of relatively widespread and mostly polyploid, apomictic populations that include the type. It was recognized after preparation of this treatment that E. novae-angliae (E. leucolepis var. novae-angliae) was derived from hybridization between the unnamed diploid and E. perfoliatum, and is here recognized as a distinct species; it is not directly related genetically to E. leucolepis and thus is not appropriately classified as a variety of it. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eupatorium resinosum is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 469. | FNA vol. 21, p. 472. | ||||
Parent taxa | Asteraceae > tribe Eupatorieae > Eupatorium | Asteraceae > tribe Eupatorieae > Eupatorium | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | E. glaucescens var. leucolepis | |||||
Name authority | (de Candolle) Torrey & A. Gray: Fl. N. Amer. 2: 84. (1841) | Torrey ex de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 176. (1836) | ||||
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