Eupatorium steelei E. E. Lamont
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Authority
Lamont, E. E. 1995. Taxonomy of
section (Asteraceae). Mem. New York Bot. Gard. 72: 1-68. -
Family
Asteraceae
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Scientific Name
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Description
Species Description - Erect herb, 0.6-2 m tall. Stems solid, greenish-purple or sometimes evenly purplish, conspicuously glandular pubescent nearly or quite to the base with long, spreading, persistent hairs, occasionally merely densely puberulent and sparingly glandular. Leaves firm, mostly in 3’s or 4’s; blades lance-ovate or ovate to deltate-ovate, mostly 7-30 cm long, 2.5-18 cm wide, relatively abruptly or sometimes gradually tapering to the short-petiolate base, acuminate at the apex, pinnately veined, sharply serrate, adaxial surface glabrescent to more often scabrous-hirsute, abaxial surface conspicuously to sparsely glandular pubescent and loosely hirsute on the midrib and main veins, usually rather sparsely so over the surface as well; petioles usually (0.7-)1.3-2.8(-3.6) mm long, glabrate to densely ciliate. Inflorescence a loosely convex compound cyme, usually less than 20 cm wide in life, heads short pedunculate, peduncles conspicuously glandular pubescent. Involucre 6.5-9 mm high, 3.5-5 mm wide, often purplish; bracts 10-22, lanceolate, obtuse at apex, well imbricate, few-striate or at least with prominent midvein; receptacle naked, flat or weakly convex. Flowers (5-)6-9(-10) in a head; corolla 4.5-7.5 mm long, 5-toothed, generally very pale pinkish or purplish, funnelform, outer surface usually minutely atomiferous-glandular, lobes ovate to deltate, usually slightly longer than wide; style base puberulous, enlarged. Achenes prismatic, 3.0-4.5 mm long, 5-ribbed, atomiferous-glandular, sometimes with a few setulae along the nerves; pappus a single series of 25-40 slender, capillary, scabrous, persistent bristles. 2n = 20.
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Discussion
Type. United States. Virginia. Wise Co.: Stone Mt., 0.8 km N of High Knob Lookout Tower, 3.6 km S of Norton, 3800 ft. (1160 m), 7 Aug 1989, Lamont & Wieboldt 357 (holotype, NY!; isotypes, GH!, MO!, NY!, US!, VPI!). Eupatorium steelei (Figs. 27 & 28) is closely related to E. purpureum L., a species of wide distribution throughout eastern North America. The former can be readily distinguished by its persistently glandular-hairy stems, glandular-hairy abaxial leaf surface, and lack of concentrated anthocyanic pigment at leaf nodes. In addition, E. steelei is a coarser plant with firmer leaves that are broader in shape and are more abruptly contracted to the petiole than in E. purpureum. Eupatorium steelei has been collected in close proximity to E. purpureum and E. fistulosum. At one station in Wise Co., Virginia (near the type locality), E. steelei was found growing with E. purpureum. Both species maintained their morphological identity, but there were a few putative hybrids. Introgressive hybridization within Eupatorium is not uncommon and has been well documented in North American species (Sullivan, 1972). It would appear that E. steelei is more closely related to E. purpureum than to E. fistulosum, but all three stand as a closely related and apparently monophyletic group.
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Distribution
Habitat and distribution. Usually on gentle slopes of degraded sandstone and shale, in openings of Acer rubrum, Liriodendron tulipifera, Quercus velutina, Q. borealis, and Q. alba, above 700 m (2300 ft). The species is particularly common on hilltops, from which it colonizes roadbanks below. Eupatorium steelei is known from the Blue Ridge Province of western North Carolina (Avery, Haywood, and Macon Cos.) and eastern Tennessee (Sevier Co.), the Ridge and Valley Province of southwestern Virginia
United States of America North America|