Eupatorium

Hemp agrimony Eupatorium cannabinum, copyright Evelyn Simak.

Belongs within: Asteroideae.

Eupatorium is a Holarctic genus of perennial herbs bearing flowers in clusters of discoid heads.

Characters (from Flora of North America): Perennials, 30–200 cm. Stems erect, usually not branched proximal to arrays of heads (from caudices or rhizomes). Leaves mostly cauline; usually opposite (rarely whorled, distal sometimes alternate); petiolate or sessile; blades usually 3-nerved from or distal to bases, or pinnately nerved, mostly deltate or ovate to lanceolate or linear (and intermediate shapes, sometimes elliptic, oblong, rhombic, or suborbiculate, sometimes pinnatifid, 1–2-pinnately, ternately, or palmately lobed), ultimate margins entire or toothed, faces glabrous or puberulent, pubescent, scabrous, or setulose, usually gland-dotted. Heads discoid, in corymbiform or diffuse to dense, paniculiform arrays. Involucres obconic to ellipsoid, 1–3(–5+) mm diam. Phyllaries persistent, 7–15+ in 2–3(–4+) series, (usually green) 2–3-nerved, or not notably nerved, or pinnately nerved, elliptic, lanceolate, oblong, or obovate, usually unequal, sometimes ± equal (margins scarious, hyaline, apices rounded to acute or acuminate sometimes mucronate, faces usually puberulent or villous, usually gland-dotted, rarely glabrous). Receptacles flat or convex, epaleate. Florets (3–)5(–15+); corollas usually white, rarely pinkish, throats funnelform to campanulate, lobes 5, triangular; styles: bases sometimes enlarged, usually puberulent (rarely glabrous), branches mostly filiform. Cypselae (brownish to black) prismatic, 5-ribbed, usually glabrous, usually gland-dotted; pappi persistent, of 20–50 (whitish) barbellulate bristles in 1 series. x = 10.

<==Eupatorium
    |--E. cabaionum J87
    |--E. cannabinum LDB98
    |--E. capillifolium ACW01
    |--E. elphantus BM76
    |--E. flavidulum J87
    |--E. glabrum BT87
    |--E. glehni T03
    |--E. hemiteropododum BT87
    |--E. illitum J87
    |--E. microchaetum J87
    |--E. mikaniodes M83
    |--E. nervosum J87
    |--E. odoratum G01
    |--E. polystachyum RJ11
    |--E. porphyrocladium J87
    |--E. puberulum J87
    |--E. purpureum C38
    |--E. rugosum EBS98
    |--E. selleanum J87
    |--E. stigmaticum J87
    `--E. urbanii J87

*Type species of generic name indicated

REFERENCES

[ACW01] Aguilar, H., C. C. Childers & W. C. Welbourn. 2001. Relative abundance and seasonal occurrence of mites in the family Tydeidae on citrus in Florida. In: Halliday, R. B., D. E. Walter, H. C. Proctor, R. A. Norton & M. J. Colloff (eds) Acarology: Proceedings of the 10^th International Congress pp. 376–380. CSIRO Publishing: Melbourne.

[BT87] Baker, E. W., & D. M. Tuttle. 1987. The false spider mites of Mexico (Tenuipalpidae: Acari). United States Department of Agriculture, Technical Bulletin 1706: 1–237.

[BM76] Bohart, R. M., & A. S. Menke. 1976. Sphecid Wasps of the World. University of California Press: Berkeley.

[C38] Crawford, J. C. 1938. Some new or little known Thysanoptera. Proceedings of the Entomological Society of Washington 40 (2): 35–43.

[EBS98] Elliott, K. J., L. R. Boring & W. T. Swank. 1998. Changes in vegetation structure and diversity after grass-to-forest succession in a southern Appalachian watershed. American Midland Naturalist 140: 219–232.

[G01] Gupta, S. K. 2001. A conspectus of natural enemies of phytophagous mites and mites as potential biocontrol agents of agricultural pests in India. In: Halliday, R. B., D. E. Walter, H. C. Proctor, R. A. Norton & M. J. Colloff (eds) Acarology: Proceedings of the 10^th International Congress pp. 484–497. CSIRO Publishing: Melbourne.

[J87] Judd, W. S. 1987. Floristic study of Morne La Visite and Pic Macaya National Parks, Haiti. Bulletin of the Florida State Museum—Biological Sciences 32 (1): 1–136.

[LDB98] Lenssen, J. P. M., G. E. ten Dolle & C. W. P. M. Blom. 1998. The effect of flooding on the recruitment of reed marsh and tall forb plant species. Plant Ecology 139: 13–23.

[M83] Myers, R. L. 1983. Site susceptibility to invasion by the exotic tree Melaleuca quinquenervia in southern Florida. Journal of Applied Ecology 20: 645–658.

[RJ11] Rising, J. D., A. Jaramillo, J. L. Copete, P. G. Ryan & S. C. Madge. 2011. Family Emberizidae (buntings and New World sparrows). In: Hoyo, J. del, A. Elliott & D. A. Christie (eds) Handbook of the Birds of the World vol. 16. Tanagers to New World Blackbirds pp. 428–683. Lynx Edicions: Barcelona.

[T03] Tsurusaki, N. 2003. Phenology and biology of harvestmen in and near Sapporo, Hokkaido, Japan, with some taxonomical notes on Nelima suzukii n. sp. and allies (Arachnida: Opiliones). Acta Arachnologica 52: 5–24.