Thalictrum

Thalictrum
Thalictrum flavum
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
Order:	Ranunculales
Family:	Ranunculaceae
Genus:	Thalictrum Tourn. ex L.
Species
See text.

Thalictrum ( /əˈlɪktrəm/) is a genus of 120-200 species of herbaceous perennial flowering plants in the Ranunculaceae (buttercup) family native mostly to temperate regions. Meadow-rue is a common name for plants in this genus.

Thalictrum is a taxonomically difficult genus with poorly understood species boundaries; it is in need of further taxonomic and field research for clarification.

Despite their common name of "meadow-rue", Thalictrum species are unrelated to the true rue (family Rutaceae), but resemble its members in having the petiole twice or thrice divided.

Description

Meadow-rue leaves are alternate, bipinnately compound, and commonly glaucous blue-green in colour.

The flowers are small and apetalous (no petals), but have numerous long stamens, often brightly white, yellow, pink or pale purple, and are produced in conspicuous dense inflorescences. In some species (e.g. T. chelidonii, T. tuberosum), the sepals are large, brightly coloured and petal-like, but in most they are small and fall when the flower opens or soon after.

Ecology

Meadow-rues are usually found in shaded or damp locations, with a sub-cosmopolitan range throughout most of the Northern Hemisphere and also south to southern Africa and tropical South America, but absent from Australasia. They are most common in temperate regions of the world, twenty-two species are found in North America.

Thalictrum species are used as food plants by the larvae of some Lepidoptera species including the Setaceous Hebrew Character moth.

Selected species

Thalictrum alpinum – alpine meadow-rue Thalictrum aquilegiifolium – greater meadow-rue Thalictrum chelidonii Thalictrum cooleyi – Cooley's meadow-rue Thalictrum coreanum Thalictrum dasycarpum Thalictrum delavayi – Chinese meadow-rue Thalictrum dioicum – early meadow-rue Thalictrum fendleri – Fendler's meadow-rue Thalictrum filamentosum Thalictrum flavum – yellow or common meadow-rue

Thalictrum glaucum Thalictrum heliophilum – cathedral meadow-rue Thalictrum kiusianum – Kyushu meadow-rue, dwarf meadow-rue Thalictrum minus – lesser meadow-rue Thalictrum occidentale – western meadow-rue Thalictrum polygamum – tall meadow-rue Thalictrum pubescens Thalictrum rochebrunnianum Thalictrum sparsiflorum – fewflower meadow-rue Thalictrum thalictroides – rue-anemone (syn. Anemonella thalictroides) Thalictrum tuberosum Thalictrum urbainii

• Photos
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  Thalictrum aquilegifolium
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  Thalictrum chelidonii
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  Thalictrum coreanum
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  Thalictrum dasycarpum
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  Thalictrum delavayi flowers
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  Early meadow-rue (Thalictrum dioicum)
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  Thalictrum filamentosum
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  Thalictrum flavum leaves
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  Thalictrum glaucum flowers
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  Thalictrum kiusianum
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  Female flowers of Thalictrum occidentale
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  Thalictrum rochebrunnianum
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  Rue-anemone (Thalictrum thalictroides)
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  Thalictrum tuberosum
• 
  Thalictrum urbainii

Chemical constituents

Thalictrum species have been extensively studied by chemists. Typical natural products found in this genus are benzylisoquinoline alkaloids such as magnoflorine and the structurally related alkaloid berberine.