Tiarella trifoliata var. laciniata
Tiarella trifoliata var. trifoliata
Tiarella trifoliata var. unifoliata

General:
Perennial herb from scaly rhizomes; flowering stems 20-50 cm tall, with a few leaves, glandular-hairy above.

Leaves:
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.

Flowers:
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.

Fruits:
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.

Notes:
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