Tiarella trifoliata (L.)

Three-leaf foamflower


The Basics

Taxonomy: Kingdom - Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (Flowering plants). Class - Magnoliopsida. Order - Rosales. Family - Saxifragaceae (Saxifrage family). Genus -Tiarella L. Species - Tiarella trifoliata L.

Ecology: 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.


General: Herbaceous perennial from slender rhizomes, the flowering stems 2-3.5 dm. tall, glandular-pubescent.

Leaves: Basal leaves with petioles 2-3 times as long as the blades; leaf blades highly variable, cordate, 1.5-8 cm. long and up to 12 cm broad, trifoliate and the leaflets deeply divided, or trifoliate and the leaflets shallowly lobed, or palmately 3- to 5 lobed; cauline leaves few and reduced.

Flowers: Inflorescence an elongate, leafless panicle; calyx bell-shaped, irregular, the 5 lobes longer than the tubular section, the upper lobe the largest; petals 5, white, linear, similar to the filaments; stamens 10, the filaments opposite the petals much shorter that the alternate 5.

Fruits: Ovary superior; carpels 2, unequal, 3-5 mm. and 7-10 mm. long respectively.


Three-leaf foamflower (Tiarella trifoliata) is a Perennial forb/herb that blooms from May through August.

Species Distribution


E-Flora of British Columbia
In Klinkenberg, Brian. (Editor) 2015. E-Flora BC: Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver.

USDA Plants Database
USDA, NRCS. 2017. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
Distribution Map photo credit

Jepson eFlora: Taxon Page
Michael S. Park & Patrick E. Elvander 2017. Tiarella trifoliata, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=46560, accessed on February 13, 2017.

Flora of North America
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 19+ vols. New York and Oxford.

Burke Museum of Natural History and Culture
Burke Museum. 2017. Tiarella trifoliata [Online]. University of Washington.
Photo credit: 2004, Ben Legler