E-Flora BC: Electronic Atlas of the Flora of British Columbia

Tiarella trifoliata L.
three-leaved foamflower (cut-leaved foamflower (var. laciniata); one-leaved foamflower (var. unifoliata); threeleaf foamflower; three-leaved foamflower (var. trifoliata))
Saxifragaceae (Saxifrage family)

Introduction to Vascular Plants

© Paul Dawson  Email the photographer   (Photo ID #86263)

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Distribution of Tiarella trifoliata
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Species Information

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Perennial herb from scaly rhizomes; flowering stems 20-50 cm tall, with a few leaves, glandular-hairy above.
Basal leaves heart-shaped, 3-12 cm wide, about as long, simple and shallowly to deeply 3- to 5-lobed or compound with 3 stalked leaflets that are lobed or deeply cleft, almost to the base, toothed, hairy and usually glandular, the stalks longer than blades, stipules about 1 cm long; stem leaves similar to the basal, 2 or 3, reduced; stipules to 1 mm long.
Inflorescence a narrow, many-flowered, terminal cluster, up to 15 cm long, densely glandular-hairy; petals 3-4 mm long, thread-like; calyces bell-shaped, 1.5-2.5 mm long, glandular-hairy, hypanthium bell-shaped, free of ovary, lobed 1/2 to 2/3 length, lobes irregular, the upper lobe largest; stamens 10.
Capsules, borne horizontally, one valve 3-5 mm long, the other 7-10 mm long; seeds blackish, about 1.5 mm long, shining, nearly smooth.
Three infraspecific taxa have been recognized. These taxa are widely sympatric but var. trifoliata generally occurs at lower elevations (up to 650 m), while var. unifoliata generally occurs above 650 m. Variety laciniata is a hybrid between the latter two and occurs frequently on Vancouver Island and sporadically on the mainland.

1. Leaves simple, shallowly to deeply 3- to 5-lobed........... var. unifoliata (Hook.) Kurtz1.

1. Leaves compound, with 3 stalked leaflets.

2. Leaflets lobed............. var. trifoliata

2. Leaflets deeply cleft, almost to the base............. var. laciniata (Hook.) Wheelock

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist forests, meadows and streambanks in the lowland and montane to subalpine zones; common throughout BC south of 58degreeN; N to the Aleutian Islands and S AK, E to AB and S to MT, ID and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Tiarella trifoliata

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 0 665 2750
Slope Gradient (%) 0 20 350
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 345 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 4 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: AT(1), BWBS(7), CDF(170), CWH(2337), ESSF(823), ICH(867), IDF(10), MH(129), MS(22), PP(1), SBPS(7), SBS(938), SWB(2)

Ecological Indicator Information

Shade-tolerant/intolerant, submontane to subalpine, Western North American forb distributed more in the Pacific than in the Cordilleran region. Occurs in hypermaritime to maritime climate on fresh to very moist, nitrogen-rich soils; occurrence decreases with increasing latitude, elevation, and continentality. Scattered to abundant on water­receiving sites that support a very productive growth of Douglas-fir, Sitka spruce, true firs, and western redcedar. Often grow with Achlys triphylla, Athyrium filix-femina, Galium triflorum, Polystichum munitum, Rubus paroifIorus, and R. spectabilis. A nitrophytic species characteristic of Moder and Mull humus forms.

SourceIndicator Plants of Coastal British Columbia (Information applies to coastal locations only)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is cool temperate & cool mesothermal.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References