Triodanis perfoliata

From Puget Prairie Plants
  • Scientific Name: Triodanis perfoliata
  • Family: Campanulaceae
  • Common Names: Venus' looking glass, clasping bellwort
  • Previous names and misapplications: Specularia perfoliata

Triodanis perfoliata. Photo Ben Legler 2011


Scientific classification
Kingdom: Plantae
Subkingdom: Viridiplantae
Phylum: Tracheophyta
Subphylum: Spermatophytina
Class: Magnoliopsida
Subclass: Asteranae
Order: Asterales
Family: Campanulaceae
Genus: Triodanis Raf ex. Greene
Species: Triodanis perfoliata (L.) Nieuwl.
  • Legousia perfoliata (L.) Britton
  • Specularia perfoliata (L.) A. DC.


Annual herb growing from taproot[2] with axillary purple flowers, to 60 cm tall.[3] Stems erect, usually simple or sometimes branched, hairy.[4] Leaves cauline, alternate, clasping, cordate to rotund, 0.5-3 cm long, lowest leaves narrow and short-petiolate.[4] Flowers axillary on upper stem with 1 to several in each axil,[3] radially symmetrical; calyx, corolla and androecium inserted on hypanthium; sepals 5, narrowly triangular, sometimes connate at base; corolla 5-lobed, rotate,[2] 8-13 mm long;[4] stamens 5;[3] pistil 3-carpellate,[5] with 1 to 3-lobed style, inferior ovary becoming an elliptic to oblong capsule, dehiscent by distal pore.[2]

Bloom Period

April - June[3]


Southern British Columbia to California; mainly west of the Cascade crest in Washington, both sides of Cascades in Oregon and California.[2]


Common weed species growing in waste places, disturbed sites, pastures, prairies, and roadsides [6]. Dry woods and open sites (Justice and Bell, 1968). Dry to moderately dry soils [7].


Site Rehabilitation

Useful for attracting pollinating insects. Fibrous roots have the capacity to stabilize disturbed soils [8] [9]


Attracts mega-chilid bee, sphecid wasps, leatherwing beetles [10]


Annual species but possible to mass in beds for pleasing purple colour.

First Nations

Liquid compound of root taken for dyspepsia from overeating; Infusion of roots taken and used as a bath for dyspepsia; Use as an emetic.[11]


Seed Propagation

  • Seed collection time: June-August
  • Crop intervals: Annual

Fruit and Seed Collection and Extraction

Collect capsules by hand into collection bags. Allow to dry, and then shake collection bags to release seeds.

Fruit/Seed Dormancy and Treatment

Sow seeds outdoors in flats or containers in late summer or early fall and allow dormancy to be broken naturally.

Outplanting Characteristics and Requirements

Plant in full sun to partial shade in coarse-textured, free-draining soils.

Photo Gallery


  1. Interagency Taxonomic Information System. Retrieved from
  2. 2.0 2.1 2.2 2.3 Hitchcock, C. L., Cronquist, A., Giblin, D., & Legler, B. et al. (2018). Flora of the Pacific Northwest: an illustrated manual. Seattle: University of Washington Press. p. 517.
  3. 3.0 3.1 3.2 3.3 WTU Herbarium, Burke Museum, & University of Washington. (n.d.). Retrieved from
  4. 4.0 4.1 4.2 E-Flora BC: Electronic Atlas of the Flora of British Columbia. Retrieved from
  5. Zomlefer, W. (1994). Guide to Flowering Plant Families. Chapel Hill, NC: The University of North Carolina Press. p. 211.
  6. Seyermark, 1963
  7. Douglas et al, 2002
  8. USDA, 2002
  9. Haddock, 2000
  10. Gara and Meunhow, 1990
  11. Native American Ethnobotany Database. (n.d.). Retrieved from

Garry Oak Ecosystems Recovery Team Propagation Guidelines