Tiarella trifoliata


Sp. Pl. 1: 406. 1753 ,.

Common names: Three-leaf foamflower
Treatment appears in FNA Volume 8. Treatment on page 115.

Flowering stems 10–70 cm


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Alta., B.C., Alaska, Calif., Idaho, Mont., Oreg., Wash.


Varieties 3 (3 in the flora).

Varieties of Tiarella trifoliata have overlapping ranges and differ from each other in leaf form and marginal dissection. Their floral features are stable throughout. They were previously suspected of hybridizing when sympatric. They are differentiated along elevational gradients and often remain distinct in sympatric populations.

Selected References



1 Basal leaves usually simple; cauline leaves rarely trifoliolate, shallowly to deeply lobed, leaflets sessile. Tiarella trifoliata var. unifoliata
1 Basal leaves 3-foliolate; cauline leaves 3-foliolate; leaflets deeply lobed, petiolulate > 2
2 Leaflet lobes to 1/2 length of leaflet, distal segments not laciniate. Tiarella trifoliata var. trifoliata
2 Leaflet lobes more than 1/2 length of leaflet, distal segments laciniate. Tiarella trifoliata var. laciniata