Thalictrum dasycarpum

Tall Meadowrue

Tall Meadowrue, Photo © by Earl J.S. Rook
Tall Meadowrue
Photo © by Earl J.S. Rook

Flora, fauna, earth, and sky...
The natural history of the northwoods


Name:

  • Thalictrum, from the Greek, qaliktron (thaliktron), name for the European meadowrue Thalictrum minus.
  • dasycarpum, from the Greek dasus (dasus), "hairy, bushy, thick grown", and karpos (karpos), "fruit".
  • Common name from its height relative to our other meadowrues, and from the habitat of some Thalictrum (though not necessarily this one) and rue, from the Anglo-Saxon rúde, and the Peloponnesian Greek `ruth (hrute), a name originally given to Ruta graveolens and later applied to a host of plants with bitter leaves.
  • Other common names include Purple Meadowrue.

Taxonomy:

  • Kingdom Plantae, the Plants
    • Division Magnoliophyta, the Angiosperms (flowering plants)
      • Class Magnoliopsida, the Dicotyledons 
      • Subclass Magnoliidae
        • Order Ranunculales, the Buttercups
          • Family Ranunculaceae, the Buttercups, with Actaea, the Baneberries, Clematis, Coptis (Gold Thread), Delphinium (Larkspurs), Hepatica, Ranunculus (Buttercups), and Thalictrum (Meadow Rues).
            • Genus Thalictrum, the Meadowrues; about 100 species of perennial herbaceous plants, from the North Temperate Zone, South America, and Africa
  • Taxonomic Serial Number: 18667
  • Also known as Thalictrum hypoglaucum

Description:

  • A ¼, ½, ¾,  º, é
  • 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). Lowest leaves petiolate, middle and upper leaves becoming sessile, all leaves ternately compound. Leaflets green, typically 3-lobed, typically longer than broad, glabrous to puberulent below, to 5cm long, 4cm broad. Lobes acute, sometimes divided. Margins sometimes slightly revolute.
  • Stem erect, stout, 16"-60"(to 6'6"), glabrous, purple, herbaceous, fistulose, from caudex, branching above or simple, typically single from base.
  • Roots 
  • Flowers 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; Inflorescence - Plants dioecious.
    • Male (staminate) inflorescence a large open terminal panicle, very showy. Pedicels 5-6mm long, glabrous, each subtended by a small attenuate bract to 1.5mm long.Staminate flowers apetalous. Sepals 4, white, elliptic-lanceolate, 3mm long, 1.7mm broad, glandular pubescent externally, glabrous internally, fugacious. Stamens +/-12 in number. Filaments white, slightly clavate, 4mm long, glabrous. Anthers yellow, 1.2mm long, -1mm broad, apiculate.
    • Femaile (pistillate) inflorescence paniculate, terminal, not showy. Peduncles to 5mm long, glabrous. Pistillate flowers with +/-10 carpels. Styles whitish at apex. Sepals green, +/-2mm long.
      • Sepals 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.
      • Petals 
      • Stamens 
      • Pistils
      • Ovary superior (within blossom) inferior (below flower) 
  • Fruit a achene; 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.
  • A dense, clump-forming meadow rue growing 3-5' tall. Features lacy, fine-textured, medium green, compound foliage (superficially resembling columbine or maidenhair fern) and terminal, wiry-branched sprays (panicles) of tiny, purplish-white flowers which appear in early summer (late May-July). Individual flowers are not particularly striking, but mass effect of bloom can be quite showy. Stems are often purple. Mostly dioecious (male and female flowers on separate plants). Male flowers have showy yellow stamens..

Identification:

  • Identifiable as a Meadowrue (Thalictrum species) by its three times compound, lobed leaves, resembling those of Columbine (Aquilegia canadensis) or Maidenhair Fern (Adiantum pedantum), and by its flowers without petals.
  • Distinguished from our two smaller meadowrues by
  • Distinguished with difficulty from our other large meadowrue
  • The staminate plants can be quite showy in flower but the pistillate plants are often overlooked. This species and another, T. revolutum DC., can be very difficult to distinguish from one another. A third species, T. diocum L., is easier to distinguish because it blooms in the spring and has middle and uper leaves which are long petiolate instead of sessile.
  • Field Marks

Distribution:

  • British Columbia to Québec, south to Idaho, Montana, Wyoming, Colorado, Arizona, New Mexico, Texas, Louisiana, Mississippi, Alabama, Kentucky, Ohio, and Pennsylvania.

Habitat:

  • Deciduous, riparian woods, damp thickets, swamps, wet meadows, and prairies.

Fire:

Associates:

  • Trees:
  • Shrubs:
  • Herbs:
  • Ground Covers:
  • Mammals:
  • Birds:

History:

Uses:

Reproduction:

  • Sexually by seed
  • Flowers
  • Assexually by

Propagation:

  • By rhizome division,

Cultivation:

  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Cultural Requirements
    • Light:
    • Soil:
    • Water:
    • Spacing:
    • Fertilization:
  • Size 12"-18"W x 12"-18"H
  • Growth rate
  • The lacy, blue-green foliage make this plant an excellent companion for showy spring and summer flowers. In late spring, the plants produce either male or female flowers, each covered with dozens of delicate white and yellow flowers. The seeds were used as a perfume by the Teton Dakota Indians. Prefers rich, moist soil, and looks great when planted along streambanks and pond edges. Grows three to six feet tall in full sun to medium shade.
  • No serious insect or disease problems. Powdery mildew and rust are only occasional problems. Taller plants may need staking or other support.
  • Cultivars include
    • variety 'Alba', with
  • Cultivars and species available by mail order from specialty suppliers or at local nurseries

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Last Updated on 29 September, 2002