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.


General: Erect annual herbs, the stems erect, usually simple, 1-6 dm. tall, the surface rough.

Leaves: Leaves alternate, sessile, cordate-clasping, rotund-ovate, palmately veined, the leaves 0.5-3 cm. long and wide, or the lowermost ones narrower, more obovate, and short-petiolate.

Flowers: Flowers sessile in the axils of the middle and upper leaves, 1-several in each axil, in a leafy, spike-like arrangement; calyx lobes 5, divided to the base, narrowly triangular and pointed, 5-8 mm. long; corolla united, regular, the 5 lobes longer than the tube, 8-13 mm, long, deep purple to pale lavender; stamens 5, free from the corolla and from each other; the lower flowers do not open and the calyx of these is smaller and 3- or 4-lobed; ovary inferior.

Fruit: Capsules oblong, 2- or 3-celled, about 1 cm. long in the open flowers, half that size in the others.[1]

Bloom Period

  • Flowering time: May to June
  • Fruit ripening time: June to July



Common weed species growing in waste places, disturbed sites, pastures, prairies, and roadsides [2]. Dry woods and open sites (Justice and Bell, 1968). Dry to moderately dry soils [3].


Site Rehabilitation

Useful for attracting pollinating insects. Fibrous roots have the capacity to stabilize disturbed soils [4] [5]


Attracts mega-chilid bee, sphecid wasps, leatherwing beetles [6]


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; Used as an emetic.[7]


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. WTU Herbarium, Burke Museum, & University of Washington. (n.d.). Retrieved from
  2. Seyermark, 1963
  3. Douglas et al, 2002
  4. USDA, 2002
  5. Haddock, 2000
  6. Gara and Meunhow, 1990
  7. Native American Ethnobotany Database. (n.d.). Retrieved from

Garry Oak Ecosystems Recovery Team Propagation Guidelines