This perennial wildflower is 3-9' tall and largely unbranched, except for some lateral ascending stems along the upper one-third of its length. The central stem is dark purple to pale purplish white, stout, terete, glabrous, and glaucous; the interior of the central stem is mostly hollow. The lateral stems are similar, except they are more narrow. Whorls of 4-7 leaves (usually 5-6) occur at intervals along the central stem; whorls of smaller leaves also occur along some of the lateral stems. Individual leaves are up to 9' long and 3' across; they are elliptic in shape and crenate-serrate along their margins. The upper leaf surface is medium green and glabrous; it is creased along the veins. The lower leaf surface is pale green and mostly glabrous, except for hairs along the lower sides of the veins. The petioles are up to ½' long, pale purple to dark purple, and stout. The central stem terminates in a panicle of flowerheads up to 1½' long and 1' across; the upper lateral stems often terminate in panicles of flowerheads as well, except they are smaller in size. Individual panicles are rather open and dome-shaped at the top; they vary in color from pale pink-lavender to deep rosy pink. Individual flowerheads are about 9 mm. (1/3') long and 3 mm. (1/8') across, consisting of 5-7 disk florets and no ray florets. Each disk floret consists of a narrowly cylindrical corolla with 5 upright lobes, 5 inserted stamens, and a pistil with an exserted bifurcated style. The corolla is pink-lavender to rosy pink. At the base of each flowerhead, there are overlapping bracts (phyllaries) that are appressed together in several series. These bracts are usually linear-oblong, white with pink tints to light pink, and glabrous. The branches of each panicle are widely spreading to ascending; they are usually dark purple and finely pubescent. The blooming period occurs from mid-summer to early fall and lasts about 1 month. The flowerheads are often mildly fragrant. Afterwards, the disk florets are replaced by small bullet-shaped achenes (about 3 mm. long) with tufts of bristly hair. They are distributed by the wind. The root system is mostly fibrous, although sometimes rhizomes are produced.

Hollow-Stemmed Joe-Pye Weed is an uncommon plant that is found in the southern tip of Illinois, SE Illinois, and widely scattered areas elsewhere. Habitats include wet sand prairies, seeps and springs in partially wooded areas, soggy thickets, fens, rocky sandstone ravines along streams, and low areas along railroads and roadsides. Sometimes this wildflower is cultivated in gardens, although many cultivars display some evidence of hybridization.

Eupatorium fistulosum Barratt:
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.

Eupatoriadelphus fistulosus (Barratt) R.M. King & H. Rob.:
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.

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Plants 60–350+ cm. Stems usually purple throughout, sometimes greenish or purple-spotted, hollow proximally, usually glabrous proximally (rarely pubescent toward bases when young), ± glandular-puberulent distally and among heads (glaucous throughout, at least when fresh). Leaves mostly in 4s–6s(–7s); petioles (5–)10–30(–50) mm, glabrous; blades pinnately veined, narrowly to broadly lanceolate, mostly (8–)12–25(–28) × (1.5–)2–6(–9) cm, bases gradually tapered, margins finely serrate (teeth rounded, blunt), abaxial faces sparingly and minutely ± scabrellous to glabrate, adaxial faces glabrous or sparingly puberulent. Heads in convex to rounded (dome-shaped), compound corymbiform arrays (ultimately broadly cylindric). Involucres often purplish, 6.5–9 × 2.5–5 mm. Phyllaries glabrous or outer with hairs on midveins. Florets (4–)5–7; corollas usually pale pinkish or purplish, 4.5–6 mm. Cypselae 3–4.5 mm. 2n = 20.

Eupatorium fistulosum Barratt, Eupatoria Verticillata, no. 1. 1841; Eupatoriadelphus fistulosus (Barratt) R. M. King & H. Robinson; Eupatorium purpureum Linnaeus var. angustifolium Torrey & A. Gray

Hollow-Stemmed Joe-Pye Weed is an uncommon plant that is found in the southern tip of Illinois, SE Illinois, and widely scattered areas elsewhere. Habitats include wet sand prairies, seeps and springs in partially wooded areas, soggy thickets, fens, rocky sandstone ravines along streams, and low areas along railroads and roadsides. Sometimes this wildflower is cultivated in gardens, although many cultivars display some evidence of hybridization.

The flowerheads are visited by honeybees, bumblebees, and other long-tongued bees; other floral visitors include bee flies (Bombyliidae), butterflies, skippers, and moths. Most of these visitors obtain nectar from the flowerheads, although some bees also collect pollen. A modest number of insects feed on the foliage, flowers, stems, or roots of Hollow Joe-Pye Weed and other members of this genus. They include caterpillars of the following moths

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

The preference is full or partial sun and wet to moist conditions; the soil can contain loam, sand, or gravel. There is considerable variation in the size of individual plants. Exposure to high winds can cause some plants to topple over. Standing water is tolerated if it is temporary.

In the field, Eutrochium fistulosum is the most distinct species of the genus; herbarium specimens do not always document the distinguishing characteristics: heights commonly surpassing 2 m, proximal stem diameters usually 2 cm or greater, stems strongly glaucous (mostly hollow, sometimes distally hollow), leaves commonly 6 or 7 per node, arrays of heads commonly 30 × 22 cm.