Asteraceae tribe Eupatorieae

Annuals, biennials, perennials, subshrubs, shrubs, or vines [trees]. Leaves usually cauline, sometimes basal or basal and cauline; usually opposite, sometimes whorled or alternate; usually petiolate, sometimes sessile; blade margins entire, toothed, lobed, or dissected. Heads homogamous (usually discoid [radiant]), usually in corymbiform, paniculiform, racemiform, or spiciform arrays, sometimes borne singly or in glomerules. Calyculi 0. Phyllaries usually persistent (readily falling), usually in 2–8+ series, distinct, and unequal, sometimes in 1–2 series, distinct, and subequal to equal, usually herbaceous to chartaceous, margins and/or apices sometimes scarious (abaxial faces often striate-nerved). Receptacles usually flat to convex, sometimes spheric or conic, usually epaleate, rarely paleate (paleae readily falling). Ray florets 0. Disc florets bisexual, fertile; corollas white, ochroleucous, or pink to purplish, not yellow, not 2-lipped (sometimes ± zygomorphic), lobes (4–)5, usually ± deltate to lance-ovate, sometimes lanceolate to lance-linear; anther bases obtuse, rounded, or truncate, not tailed, apical appendages usually ovate to lanceolate, sometimes 0; styles abaxially papillate to hirsutulous (usually distally, sometimes at bases), branches ± linear, adaxially stigmatic in 2 lines from bases to appendages, appendages usually terete to clavate (lengths often 2–5+ times lengths of stigmatic lines), usually papillate. Cypselae usually ± monomorphic within heads, usually columnar to fusiform, sometimes prismatic or compressed to flattened, rarely, if ever, beaked, bodies often 10-ribbed or (4–)5-angled, smooth or papillate to rugose between ribs or angles (glabrous or hairy); pappi (rarely 0) usually persistent, usually of fine to coarse, barbellulate to plumose bristles, sometimes of scales (scales often aristate) or awns, sometimes of bristles and scales.

Distribution

Mostly subtropics, tropics, and warm-temperate New World, also in Old World.

Discussion

Genera 170, species 2400 (27 genera, 159 species in the flora).

In a survey of Compositae, G. Bentham (1873) noted 35 genera and 750 or so species for Eupatorieae; he treated more than 50% of those species as belonging within one genus, Eupatorium. The current view of circumscriptions of most genera within Eupatorieae has stemmed largely from the work of H. Robinson, which was summarized by R. M. King and Robinson (1987), who reported 45 species for Eupatorium (i.e., ca. 2 % of the total species in the tribe).

Authors of molecular studies have repeatedly found Eupatorieae to be a coherent clade “nested” within Heliantheae (broad sense) (e.g., R. K. Jansen et al. 1990). Some of those authors have suggested inclusion of Eupatorieae within Heliantheae in the broad sense as a subtribe; others have suggested break-up of Heliantheae into a dozen or so tribes (e.g., J. L. Panero and V. A. Funk 2002).

Selected References

Gaiser, L. O. Studies in the Kuhniinae (Eupatorieae). II. J. Arnold Arbor. 35: 87–133.

King, R. M. and H. Robinson. 1987. The genera of the Eupatorieae (Asteraceae). Monogr. Syst. Bot. Missouri Bot. Gard. 22.

Schilling, E. E., J. L. Panero, and P. B. Cox. 1999. Chloroplast DNA restriction site data support a narrowed interpretation of Eupatorium (Asteraceae). Pl. Syst. Evol. 219: 209–223.

Schmidt, G. J. and E. E. Schilling. 2000. Phylogeny and biogeography of Eupatorium (Asteraceae: Eupatorieae) based on nuclear ITS sequence data. Amer. J. Bot. 87: 716–726.

Lower Taxa

Ageratina, Ageratum, Asanthus, Brickellia, Brickelliastrum, Carminatia, Carphephorus, Carphochaete, Chromolaena, Conoclinium, Eupatorium, Eutrochium, Fleischmannia, Flyriella, Garberia, Hartwrightia, Isocarpha, Koanophyllon, Liatris, Malperia, Mikania, Pleurocoronis, Sclerolepis, Shinnersia, Stevia, Tamaulipa, Trichocoronis

Key

1	Involucres narrowly cylindric, (1–)2–3 mm diam.; phyllaries 4 or 5(–6) in ± 1–2 series; florets 4 or 5(–6)	> 2
1	Involucres campanulate, cylindric, ellipsoid, hemispheric, or obconic, (2–)3–7(–25) mm diam.; phyllaries (5–)8–45(–65+) in (1–)2–8+ series; florets (3–)10–125(–200+).	> 3
2	Subshrubs or shrubs; phyllaries 5(–6); florets 5(–6)	Stevia
2	Vines; phyllaries 4; florets 4	Mikania
3	Cypselae 8–10-ribbed	> 4
3	Cypselae (3–)4–5(–8)-ribbed	> 9
4	Pappi of 0–5+, muticous, erose, lacerate, or lanceolate to subulate scales (1–4 mm) plus [5–]9–12+, aristate scales (10–15 mm)	Carphochaete
4	Pappi of 10–100+ bristles	> 5
5	Leaves basal or basal and cauline (cauline mostly sessile)	> 6
5	Leaves mostly cauline (at flowering; mostly petiolate, sometimes sessile)	> 7
6	Heads usually in spiciform or racemiform, rarely corymbiform or thyrsiform, arrays; receptacles epaleate; pappi of 12–40 coarsely barbellate to plumose bristles	Liatris
6	Heads in corymbiform to paniculiform arrays; receptacles sometimes (at least partially) paleate; pappi of 35–40 barbellulate to barbellate (subequal) bristles	Carphephorus
7	Leaves all or mostly alternate (at flowering)	Garberia
7	Leaves all or mostly opposite	> 8
8	Leaf blades deltate, lance-elliptic, lance-linear, lanceolate, lance-ovate, lance-rhombic, linear, oblong, obovate, ovate, rhombic-ovate, spatulate, or suborbiculate, margins crenate, dentate, entire, laciniate-dentate, lobed, or serrate; style bases enlarged, hairy	Brickellia
8	Leaf blades linear (distal sometimes scalelike), margins entire; style bases not enlarged, glabrous	Asanthus
9	Pappi usually 0 or of 2–6(–12), muticous or aristate to subulate scales plus 0–6(–12), setiform scales or bristles, rarely coroniform (Ageratum) or of 1–5 ± glandular setae (Hartwrightia)	> 10
9	Pappi of (5–)10–80+ barbellulate, barbellate, or plumose bristles or setiform scales	> 18
10	Pappi usually 0, rarely 1–5 ± glandular setae (Hartwrightia)	> 11
10	Pappi usually of 2–6(–12) muticous or aristate to subulate scales plus 0–6(–12),setiform scales or bristles, rarely coroniform (Ageratum)	> 14
11	Leaves basal and cauline, mostly alternate; cypselae obpyramidal (gland-dotted)	Hartwrightia
11	Leaves cauline, all or mostly opposite; cypselae prismatic (not gland-dotted)	> 12
12	Heads in dense to open, cymiform or corymbiform arrays; phyllaries 30–40; style branches ± linear to clavate (distally dilated)	Ageratum
12	Heads in tight, corymbiform to subcapitate arrays or borne singly; phyllaries 10–30; style branches ± filiform or linear-filiform (little, if at all, distally dilated)	> 13
13	Leaves sessile; phyllaries not notably nerved; receptacles epaleate; stylebases not enlarged	Shinnersia
13	Leaves petiolate or sessile; phyllaries 2- or 3-nerved; receptacles paleate(paleae similar to inner phyllaries); style bases enlarged	Isocarpha
14	Phyllaries unequal; receptacles flat to convex (not warty)	> 15
14	Phyllaries ± equal; receptacles convex to conic or hemispheric (sometimes warty)	> 16
15	Leaves mostly sessile (or nearly so), blades linear; cypselae ± fusiform	Malperia
15	Leaves petiolate, blades ovate, deltate, or rhombic to lanceolate; cypselae prismatic	Pleurocoronis
16	Leaves whorled (4 or 6 per node), blades linear; heads borne singly	Sclerolepis
16	Leaves mostly opposite (distal sometimes alternate), blades elliptic, lanceolate, or oblong; heads usually in cymiform to corymbiform arrays, sometimes borne singly	> 17
17	Leaves petiolate; involucres 3–6 mm diam.; phyllaries usually 2-nerved; pappi usually of 5–6 aristate scales, rarely coroniform	Ageratum
17	Leaves sessile; involucres 3–4(–5) mm diam.; phyllaries obscurely 3–4-nerved; pappi of 2–6 setiform scales	Trichocoronis
18	Involucres cylindric (3–4+ mm diam); pappus bristles plumose (basally coherent or connate, falling together or in groups)	Carminatia
18	Involucres usually obconic to hemispheric, sometimes campanulate, cylindric, or ellipsoid (2–7 mm diam.); pappus bristles smooth to barbellulate or barbellate (not plumose)	> 19
19	Phyllaries ± equal	> 20
19	Phyllaries unequal (outer shorter)	> 23
20	Receptacles conic	Conoclinium
20	Receptacles flat or convex	> 21
21	Phyllaries 2- or 3-nerved, or not notably nerved, or pinnately nerved; style bases usually puberulent (glabrous in Eupatorium capillifolium); cypselae usually gland-dotted	Eupatorium
21	Phyllaries 3-nerved, or 0- or 2-nerved; style bases glabrous; cypselae sometimes gland-dotted	> 22
22	Involucres 2–3 mm diam.; phyllaries 7–16 in 1–2 series; florets 3–13	Koanophyllon
22	Involucres 3–6 mm diam.; phyllaries ca. 30 in 2–3 series; florets 10–60	Ageratina
23	Style bases usually puberulent (glabrous in Eupatorium capillifolium); cypselae usually glabrous and gland-dotted, sometimes scabrellous on ribs	> 24
23	Style bases usually glabrous (hirsute in Flyriella); cypselae glabrous or hirsute, hirtellous, hispidulous, hispidulo-strigose, puberulent, or scabrellous (sometimes gland-dotted)	> 25
24	Leaves mostly opposite (sometimes whorled, distal sometimes alternate)	Eupatorium
24	Leaves mostly whorled (3–7 per node), rarely opposite	Eutrochium
25	Annuals or perennials; involucres 2–5+ mm diam.; florets 10–30	> 26
25	Perennials, subshrubs, or shrubs; involucres (2–)4–7 mm diam.; florets (3–)25–50	> 27
26	Perennials, 20–60 cm (viscid); corollas white to ochroleucous, throats ± cylindric (± contracted distally, lengths 4–6 times diams.)	Flyriella
26	Annuals or perennials, 30–120+ cm (not viscid, stems usually puberulent, hairs curled); corollas bluish, pinkish, purplish, or white, throats funnelform (not contracted distally, lengths 2.5–4 times diams.)	Fleischmannia
27	Phyllaries usually readily falling, 18–65+ in 4–6+ series, 3–5-nerved; cypselae (3–)5-ribbed, scabrellous, usually gland-dotted	Chromolaena
27	Phyllaries usually persistent, 7–35 in (1–)2–4 series, 2- or 4-nerved, 3-nerved, or obscurely nerved; cypselae 5(–7)-ribbed, hispidulous, hispidulo-strigose, puberulent, or sparsely scabrellous (sometimes gland-dotted)	> 28
28	Phyllaries 2- or 4-nerved; corollas white to yellowish white; pappi readily falling or fragile	Brickelliastrum
28	Phyllaries 3-nerved or obscurely nerved; corollas usually blue, lavender, or pinkish, sometimes white; pappi persistent	> 29
29	Involucres 5–7 mm diam.; phyllaries 30–35; florets 30–50	Tamaulipa
29	Involucres 2–3 mm diam.; phyllaries 7–16; florets 3–13	Koanophyllon