This perennial wildflower is 3-7' tall. It has a central stem that is unbranched below, becoming branched above. The stems are are usually purple, more or less terete, and either glabrous or minutely and sparingly pubescent. The alternate leaves are ternately compound; they are up to 2' long and across, becoming smaller as they ascend the stems. The lower leaves have long petioles, while the upper leaves have either short petioles or they are sessile. Individual leaflets are ¾-2' long and ½-1½' across; they are oblong-ovate or oblong-obovate in shape, while their margins are smooth and sometimes revolute (rolled downward). Individual leaflets usually have 2-3 lobes along their outer margins, but sometimes they are unlobed. The upper leaflet surface is medium green and glabrous, while the lower surface is either light green and glabrous or light grayish green and short-pubescent. The leaflets usually have short slender petiolules (basal stalklets), but sometimes the lateral leaflets in a group of 3 are sessile. The petioles, petiolules, and rachises are usually purple and glabrous, but sometimes they are light green, especially when a plant is growing in shade. Because Purple Meadow Rue is dioecious, individual plants produce either all male (staminate) flowers or all female (pistillate) flowers. Regardless of gender, the central stem of a plant terminates in a panicle of flowers about ¾-2' long and about one-half as much across. In addition, smaller panicles of flowers are often produced from the axils of upper leaves. There is a tendency for female plants to produce smaller panicles than male plants. The branches of a panicle are usually purple and glabrous. Individual male flowers are about 1/3' (8 mm.) long, consisting of 4-5 deciduous sepals and up to 15 stamens; there are no petals. The filaments of the stamens are slender and white, while the anthers are pale yellow. Individual female flowers are about 1/3 (8 mm.) long, consisting of 4-5 deciduous sepals and up to 15 pistils; there are no petals. The pistils are light green. The blooming period occurs from early to mid-summer for about 2-3 weeks. The flowers are cross-pollinated by the wind. Afterwards, the female flowers are replaced by spindle-shaped achenes that turn brown at maturity. Each achene has a beak at its apex and 4-6 raised ribs along its sides. The root system is fibrous and rhizomatous. Clonal offsets are sometimes produced from the rhizomes.

The native Purple Meadow Rue is occasional throughout Illinois; it is somewhat more common northward than southward within the state (see Distribution Map). This map refers only to the typical variety of this species. Habitats consist of river-bottom prairies, savannas and thickets, woodland borders, openings in wooded areas, wooded ravines, floodplain woodlands, swamps, and edges of fens. This wildflower has low fidelity to any particular habitat; sometimes it is found in sandy wetlands.

Thalictrum dasycarpum var. hypoglaucum (Rydb.) B. Boivin:
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.

Thalictrum dasycarpum Fisch. & Avé-Lall.:
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.

Alta., B.C., Man., Ont., Que., Sask., Yukon; Ala., Ariz., Ark., Colo., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Miss., Mo., Mont., Nebr., N.Mex., N.Y., N.Dak., Ohio, Okla., Pa., S.Dak., Tenn., Tex., Utah., Wis., Wyo.

Canada

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Stems erect, stout, 40-150(-200) cm. Leaves chiefly cauline; basal and proximal cauline petiolate, distal cauline leaves sessile or nearly so; petioles and rachises glabrous or occasionally pubescent and/or stipitate-glandular. Leaf blade: basal and proximal cauline 3-5×-ternately compound; leaflets brownish green to dark green or bright green, ovate to cuneate-obovate, apically undivided or 2-3(-5)-lobed, 15-60 × 8-45 mm, length 0.9-2.6 times width, usually leathery with veins prominent abaxially, margins often revolute, lobe margins entire, surfaces abaxially usually pubescent and/or papillose (i.e., with very minute sessile glands). Inflorescences panicles, apically ± acutely pyramidal, many flowered; peduncles and pedicels usually glabrous, rarely pubescent or stipitate-glandular. Flowers usually unisexual, staminate and pistillate on different plants; sepals 4(-6), whitish, lanceolate, 3-5 mm; filaments white to purplish, filiform, scarcely dilated distally, 2-6.5 mm, flexible; anthers 1-3.6(-4) mm, usually strongly apiculate. Achenes numerous, sessile or nearly sessile; stipe 0-1.1 mm; body ovoid to fusiform, 2-4.6 mm, prominently veined, usually pubescent and/or glandular; beak often dehiscent as fruit matures, ± straight, filiform, 1.5-4.7(-6) mm, about as long as achene body.

Thalictrum dasycarpum var. hypoglaucum (Rydberg) B. Boivin

Isotype for Thalictrum hypoglaucum Rydb.
Catalog Number: US 317
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): E. Hall
Year Collected: 1872
Locality: Dallas., Texas, United States, North America

The native Purple Meadow Rue is occasional throughout Illinois; it is somewhat more common northward than southward within the state (see Distribution Map). This map refers only to the typical variety of this species. Habitats consist of river-bottom prairies, savannas and thickets, woodland borders, openings in wooded areas, wooded ravines, floodplain woodlands, swamps, and edges of fens. This wildflower has low fidelity to any particular habitat; sometimes it is found in sandy wetlands.

Deciduous, riparian woods, damp thickets, swamps, wet meadows, and prairies; 80-2500m.

Even though honeybees and other bees are sometimes attracted to the abundant pollen of male flowers, the flowers of Purple Meadow Rue are not cross-pollinated by insects as its female flowers are devoid of nectar. There are relatively few insects that feed on the foliage, stems, and other parts of this and other Thalictrum spp. This select group of species includes the aphid Nasonovia purpurascens and caterpillars of the following oligophagous moths

Thalictrum dasycarpum (Purple Meadow Rue)
(Honeybees collect pollen; this plant is usually wind-pollinated; this observation is from Robertson)

Bees (long-tongued)
Apidae (Apinae): Apis mellifera cp

Flowering late spring-summer (May-late Jul).

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


No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 9
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

The preference is full sun to light shade, wet to mesic conditions, and soil that is loamy, slightly sandy, or slightly rocky. The size of individual plants can vary significantly depending on environmental conditions. Generally, plants growing in sunlight require more moisture than plants growing in shade.

Thalictrum dasycarpum is a variable species similar to, and possibly intergrading with, T . pubescens . Glabrous variants of T . dasycarpum have been treated as T . dasycarpum var. hypoglaucum . Glabrous and glandular (stipitate and papillate) forms are found throughout the range of the species and occur together in some populations. 

 Native Americans used Thalictrum dasycarpum medicinally to reduce fever, cure cramps, as a stimulant for horses, and as a love charm (D. E. Moerman 1986).