Eupatorium maculatum

This perennial plant is 3-5' tall and unbranched, except for flowerhead-bearing stalks near the apex of the plant. The central stem is stout, terete, and either purple-spotted or purple; it is often covered with short fine hairs. At intervals along the central stem, there are whorls of 4-5 leaves that are yellowish green or green. These leaves are up to 7" long and 2½" across; they are lanceolate to broadly elliptic and serrated along their margins. The upper leaf surfaces have conspicuous venation. The petioles of the leaves are short (less than ¼" in length). The central stem terminates in a rather flat-headed panicle of flowerheads spanning 3-6" across. Small clusters of flowerheads may occur below on separate stalks. Each narrow flowerhead is about 1/3" long, consisting of 8-20 pink to purplish pink disk florets and no ray florets. Each tiny disk floret has a narrowly tubular corolla with 5 spreading lobes along its upper rim; exerted from the corolla, there is a strongly exerted style that is divided into filiform parts. The narrow bracts (phyllaries) at the base of each flowerhead are pink or purplish pink, like the disk florets. The flowering stalks are purple-spotted to purple and they are often covered with short fine hairs. The blooming period occurs from mid- to late summer, lasting about 3-4 weeks. The flowerheads are often fragrant. The florets are replaced by achenes with small tufts of bristly hair; they are dispersed by the wind. The root system is fibrous and rhizomatous. This plant often forms small clonal colonies. Cultivation

Recently, species of Joe-Pye Weed have been separated from the Bonesets (Eupatorium spp.); they have been re-assigned to the genus Eupatoriadelphus. Many sources of information will still refer to this species as Eupatorium maculatum. In Illinois, species of Joe-Pye Weed differ from the Bonesets by their whorled leaves, while the latter group of plants have opposite leaves. Spotted Joe-Pye Weed differs from Eupatoriadelphus fistulosus (Hollow-Stemmed Joe-Pye Weed) and Eupatoriadelphus purpureus (Sweet Joe-Pye Weed) by its rather flat-headed panicles of flowerheads, purple-spotted or purplish stems that are often pubescent, and flowerheads consisting of 8-20 disk florets. Other species of Joe-Pye Weed within the state have more dome-shaped panicles of flowerheads, stems that are hairless, and flowerheads consisting of 4-7 disk florets. Spotted Joe-Pye Weed also tends to be shorter.

The native Spotted Joe-Pye Weed occurs occasionally in the northern half of Illinois, while in the southern half of the state it is rare or absent (see Distribution Map). Habitats include wet black soil prairies, wet sand prairies, sedge meadows, marshes, fens, and swampy thickets with small trees or shrubs. Spotted Joe-Pye Weed is partial to sandy wetlands, but it is also found in non-sandy wetlands. It is usually found in high quality natural areas, rather than degraded habitats with a history of disturbance.. Faunal Associations

Eupatorium maculatum L.:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Plants 60–200 cm. Stems usually purple-spotted, sometimes uniformly purple, usually solid, sometimes hollow near bases, glabrous proximally to densely puberulent throughout, glandular-puberulent distally. Leaves in (3s–)4s–5s(–6s); petioles 5–20 mm, glabrous or pubescent; blades pinnately veined, lance-elliptic to lanceolate or lance-ovate, mostly (6–)8–23(–30) × (1.5–)2–7(–9) cm, bases gradually or abruptly tapered, margins sharply serrate or doubly serrate, abaxial faces gland-dotted and densely pubescent to glabrate, adaxial faces sparingly hairy or glabrous. Heads in flat-topped, corymbiform arrays. Involucres often purplish, 6.5–9 × 3.5–7 mm. Phyllaries glabrous or densely pubescent. Florets (8–)9–20(–22); corollas purplish, 4.5–7.5 mm. Cypselae 3–5 mm. 2n = 20.

Plant height at maturity is 6'. (USDA PLANTS, 2009) Plant height is 2-7'. (Hultman, 1978) Full plant height is 60–200 cm. (FNA, 2006)

Flowers Involucres (bracts subtending the flowers head) are 6.5–9 × 3.5–7 mm. Florets are 4.5–7.5 mm. (FNA, 2006) Inflorescence is 7". (UW, 2009)

Fruit Cypselae (dry fruit with a closely adhering calyx) are 3–5 mm. (FNA, 2006)

Leaves up to 10 in. long. (NPIN, 2009) Petioles are 5–20 mm. Leaves are mostly 6-30 × 1.5–9 cm. (FNA, 2006)

Eupatorium maculatum Linnaeus, Cent. Pl. I, 27. 1755; Eupatoriadelphus maculatus (Linnaeus) R. M. King & H. Robinson; Eupatorium purpureum Linnaeus subsp. maculatum (Linnaeus) Á. Löve & D. Löve; E. purpureum var. maculatum (Linnaeus) Voss; E. trifoliatum Linnaeus var. maculatum (Linnaeus) Farwell

The native Spotted Joe-Pye Weed occurs occasionally in the northern half of Illinois, while in the southern half of the state it is rare or absent (see Distribution Map). Habitats include wet black soil prairies, wet sand prairies, sedge meadows, marshes, fens, and swampy thickets with small trees or shrubs. Spotted Joe-Pye Weed is partial to sandy wetlands, but it is also found in non-sandy wetlands. It is usually found in high quality natural areas, rather than degraded habitats with a history of disturbance.. Faunal Associations

The following is a representative barcode sequence, the centroid of all available sequences for this species.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 8
Species With Barcodes: 1

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 6
Specimens with Barcodes: 6
Species With Barcodes: 1

Rounded Global Status Rank: G5 - Secure

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure