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Late Thoroughwort, Late Eupatorium, Boneset, Whitetop

Eupatorium serotinum Michx.

Asteraceae (Sunflower Family)

▲▼ mature flowering plants

▲▼ mature flowering plants

▲▼ mature flowering plants



▲▼ flowering stems


▲▼ flowers (with common buckeye butterfly)

▲▼ flowers (with common buckeye butterfly, and pearl crescent butterfly below) 



▲▼ head inflorescence clusters


▲▼ stems and leaves


▲▼ stems and leaves 


▲ flowering stem and leaves

Eupatorium serotinum Michx., Late Boneset, Late Thoroughwort, Late Joe-Pye Weed:  (Bayer Code:  EUPSE; US Code EUSE2)

         U.S. native simple perennial, that can grow 2-6 feet tall; stems slightly ridged, green to purplish; hairy in upper portions; a few branches lower on stem, but much more branching in upper portion of plant as flowering starts

         Leaves are opposite, dark green to gray-green, lanceolate to triangular leaves with toothed margins and 3-5 prominent veins; leaves have a rough texture due to glands and hairs on leaves; leaves have obvious petioles

         Flowers are in open to semi-flat-topped clusters of head inflorescences at tips of stems; individual heads are about 0.25 inch diameter and have no ray flowers and white to gray-white or cream-white disk flowers

         Bracts below inflorescences are in multiple rows, green, oval, hairy, with round-pointed tips

         Flowering occurs late summer through mid-autumn

         Found in pastures, prairies, on right-of-ways, disturbed sites, vacant lots; tolerant of infertile soils; common in southwest Missouri pastures

         Toxic if grazed heavily; can accumulate nitrates

         May appear similar to Tall Boneset (Eupatorium altissimum), but tall boneset has lanceolate leaves that connect directly to stem (no or very short petiole), and bracts below inflorescence have a rounded tip, not pointed


         Eupatorium is a genus of plants that includes weeds called Boneset, Dogfennel, Eupatorium, Joe-Pyeweed, Thoroughwort, (all of the white-flowered species are also called whitetop.

         They are a group of perennial, native weeds that usually are not palatable to livestock, and some are poisonous

         Besides the weedy species described, there are several ornamental native species/wildflowers that were previously included in this genus group (now placed in the genus, Eutrochium), that are found in moist soils and have large terminal clusters of white, pink or blue flowers; some have whorled leavesóSweet JoePye Weed, Spotted JoePye Weed, Hollow-Stemmed JoePye Weed



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