Eutrochium

Rafinesque

New Fl. 4: 78. 1838.

Common names: Joepyeweed eupatoire
Etymology: Greek eu- , well, truly, and trocho- , wheel-like, alluding to whorled leaves
Synonyms: Eupatoriadelphus R. M. King & H. Robinson Eupatorium sect. Verticillatum de Candolle
Treatment appears in FNA Volume 21. Treatment on page 474. Mentioned on page 461, 462, 475.
 TaxonIllustrator 
FNA21 P70 Eupatorium capillifol.jpegEupatorium capillifolium
Eupatorium serotinum
Eupatorium sessilifolium
Eutrochium purpureum var. purpureum
Linny Heagy
Linny Heagy
Linny Heagy
Linny Heagy

Perennials, 30–350+ cm. Stems (sometimes ± purple, sometimes glaucous, internodes usually shorter than leaves) erect, unbranched. Leaves mostly cauline; mostly whorled (3–7 per node), rarely opposite; petiolate; blades pinnately veined or ± 3-nerved from at or near bases, deltate-ovate, lance-elliptic, lanceolate, lanceovate, or ovate (bases gradually or abruptly tapered), margins serrate (usually with gland at apex of each tooth, apices acuminate), abaxial faces usually glanddotted and hirsute, puberulent, pubescent, scabrous, or stipitate-glandular, sometimes glabrate, adaxial faces mostly puberulent to scabrous-hirsute and glabrescent, sometimes glabrate or glabrous. Heads discoid, in (flat-topped or convex to rounded) compound, corymbiform arrays. Involucres cylindric, 2.5–7 mm diam. Phyllaries persistent, 10–22 in 5–6 series, (pale-pink to purple, rarely white, tightly appressed) striate or 1-nerved, mostly lanceovate to lanceolate, unequal (outer 2–3 obtuse, densely pubescent or glabrescent, often glanddotted, innermost glabrous or glabrescent). Receptacles flat or convex, epaleate. Florets 4–22; corollas usually purplish or pinkish, rarely white, throats funnelform, lobes 5, ovate to deltate; styles: bases enlarged, puberulent, branches ± filiform to clavate (slightly dilated or flattened distally, papillose). Cypselae (dark-brown to black or yellowish-brown) prismatic, 5-ribbed, usually glanddotted, sometimes scabrellous on ribs; pappi persistent, of 25–40 (cream to pinkish purple) barbellate bristles in 1 series. x = 10.

Discussion

Species 5 (5 in the flora).

Detailed distribution maps for taxa of Eutrochium are available but treated as taxa under Eupatorium (E. E. Lamont 1995).

Key

1 Leaves usually ± 3-nerved and bases of blades abruptly contracted to petioles; florets (4–)5–9(–10) (near coast from South Carolina to New Hampshire and Nova Scotia) Eutrochium dubium
1 Leaves either pinnately veined or bases of blades gradually narrowed to petioles or both; florets 4–10 or 8–22 > 2
2 Heads in ± flat-topped arrays; florets 8–22 Eutrochium maculatum
2 Heads in convex to rounded arrays; florets 4–10 > 3
3 Stems usually glandular-pubescent throughout, sometimes densely puberulent and sparingly glandular; abaxial leaf faces ± glandular-pubescent and sparsely hirsute; s Appalachian Mountains of sw Virginia, e Kentucky, e Tennessee, and w NorthCarolina Eutrochium steelei
3 Stems glabrous proximal to heads; abaxial leaf faces sparingly and minutely gland-dotted; relatively widespread in e North America > 4
4 Stems purple at nodes, usually solid, rarely ± hollow near bases Eutrochium purpureum
4 Stems purplish throughout (and glaucous), hollow Eutrochium fistulosum

"fine" is not a number.

... more about "Eutrochium"
glabrate +, stipitate-glandular +, scabrous +, pubescent +, puberulent +  and hirsute +
glabrous +, glabrate +, glabrescent +, mostly puberulent +  and scabrous-hirsute +
not tailed +, truncate +, rounded +  and obtuse +
scarious +
usually ovate +  and lanceolate +
usually terete +  and clavate +
corymbiform +  and compound +
indeterminate +  and determinate +
Eric E. Lamont +
Rafinesque +
puberulent +
decurrent +
enlarged +
3-nerved +  and veined +
dissected +, lobed +, toothed +  and entire +
ovate;lanceovate;ovate;lanceovate;lanceolate;lance-elliptic;deltate-ovate +
papillate +  and rugose +
(4-)5-angled;10-ribbed +
less filiform;clavate +
Joepyeweed +  and eupatoire +
white +, pinkish +  and purplish +
scabrellous +
prismatic +
fertile +  and bisexual +
North America +
Greek eu- , well, truly, and trocho- , wheel-like, alluding to whorled leaves +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
in usually determinate , rarely indeterminate , arrays +  and singly +
indeterminate +
each +  and sessile +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
opposite +  and whorled +
ovate +  and deltate +
2-carpellate +
persistent +
10 +  and 22 +
bearing subulate enations +, hairy +  and bristly +
convex;flat +
lamont1995a +, mackenzie1920a +  and wiegand1937a +
exalbuminous +
appendaged +  and truncate +
hirsutulous +
papillate +
Eupatoriadelphus +  and Eupatorium sect. Verticillatum +
Eutrochium +
Asteraceae tribe Eupatorieae +
30 cm300 mm <br />0.3 m <br /> (350 cm3,500 mm <br />3.5 m <br />) +
vine +, shrub +  and subshrub +