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justiceweed, white-bract thoroughwort

semaphore thoroughwort

Habit Perennials, 40–100+ cm. Perennials, 50–100+ cm.
Stems

(from short caudices or stout rhizomes) single, sparsely branched distally, puberulent throughout (more densely distally and among heads).

(from short rhizomes, green) single, branched distally, puberulent throughout.

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.

opposite (± vertical); petiolate (petioles 10–30 mm);

blades ± 3-nerved distal to bases, deltate to rhombic, 25–80 × 20–60 mm, bases broadly cuneate, margins usually serrate (teeth uneven), sometimes crenate, apices acute, faces glabrate to sparsely puberulent, gland-dotted.

Florets

5;

corollas 3–3.5 mm.

5;

corollas 3.5–4 mm.

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.

8–12 in 2–3 series, elliptic to oblong, 1.5–5 × 0.8–1 mm, apices acute to acuminate, abaxial faces puberulent, gland-dotted.

Heads

in corymbiform arrays.

in corymbiform arrays.

Cypselae

2–3 mm;

pappi of 30–40 bristles 4.5–5 mm.

1.2–1.5 mm;

pappi of 20–35 bristles 3.5–4.5 mm.

2n

= 20.

Eupatorium leucolepis

Eupatorium mikanioides

Phenology Flowering Jul–Sep.
Habitat Moist or wet, low, often saline places
Elevation 0–10+ m (0–0+ ft)
Distribution
from FNA
AL; DE; FL; GA; LA; MA; MD; MS; NC; NJ; NY; PA; RI; SC; TN; TX; VA
[WildflowerSearch map]
[BONAP county map]
from FNA
FL
[BONAP county map]
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.)

Key
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
Source FNA vol. 21, p. 469. FNA vol. 21, p. 470.
Parent taxa Asteraceae > tribe Eupatorieae > Eupatorium Asteraceae > tribe Eupatorieae > Eupatorium
Sibling taxa
E. album, E. altissimum, E. anomalum, E. cannabinum, E. capillifolium, E. compositifolium, E. godfreyanum, E. hyssopifolium, E. lancifolium, E. leptophyllum, E. linearifolium, E. mikanioides, E. mohrii, E. perfoliatum, E. petaloideum, E. pilosum, E. resinosum, E. rotundifolium, E. semiserratum, E. serotinum, E. sessilifolium, E. ×cordigerum, E. ×pinnatifidum
E. album, E. altissimum, E. anomalum, E. cannabinum, E. capillifolium, E. compositifolium, E. godfreyanum, E. hyssopifolium, E. lancifolium, E. leptophyllum, E. leucolepis, E. linearifolium, E. mohrii, E. perfoliatum, E. petaloideum, E. pilosum, E. resinosum, E. rotundifolium, E. semiserratum, E. serotinum, E. sessilifolium, E. ×cordigerum, E. ×pinnatifidum
Subordinate taxa
E. leucolepis var. leucolepis, E. leucolepis var. novaeangliae
Synonyms E. glaucescens var. leucolepis
Name authority (de Candolle) Torrey & A. Gray: Fl. N. Amer. 2: 84. (1841) Chapman: Fl. South. U.S., 195. (1860)
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