Eupatorium leucolepis
Eupatorium lancifolium
justiceweed, white-bract thoroughwort
lanceleaf thoroughwort
(from short caudices or stout rhizomes) single, sparsely branched distally, puberulent throughout (more densely distally and among heads).
(from short rhizomes) single, branched distally, usually glabrous or glabrate, sometimes pilose.
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 or subsessile (petioles to 5 mm);
blades 3-nerved from bases, lanceolate to lance-linear, 30–50 × 5–13 mm, bases narrowly cuneate, margins serrate, apices acute, faces glabrous adaxially, sparsely pilose abaxially, densely gland-dotted.
5;
corollas 3–3.5 mm.
5;
corollas 2.5–3 mm.
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.
7–10 in 2–3 series, elliptic, 1–4.5 × 0.2–0.8 mm, apices rounded, abaxial faces pilose, gland-dotted.
in corymbiform arrays.
in corymbiform arrays.
2–3 mm;
pappi of 30–40 bristles 4.5–5 mm.
2.5–2.8 mm;
pappi of 30–40 bristles 3.5–4 mm.
= 20.
Eupatorium leucolepis
Eupatorium lancifolium
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 lancifolium has been combined with E. semiserratum or listed within it as a subspecies; it differs in its habitat as well as in having leaves that are somewhat smaller, typically a dull blue-green (in contrast to yellow-green in E. semiserratum), and 3-nerved from bases of blades.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaf blades strongly folded along midribs, curved, 4–10 mm wide | var. leucolepis |
1. Leaf blades weakly folded along midribs, not curved, 10–15 mm wide | var. novaeangliae |
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