[Coolworts and Foamflowers: The Genus Tiarella in the Cascade Mountains of Oregon and Washington]

Coolwort, Foamflower, Foam Flower, One-leaf Foamflower

Tiarella trifoliata var. unifoliata

Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata

Inflroescence of Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata)

The photo above shows a close-up of the short inflorescence (a panicle) of coolwort foamflower as photographed along the eastern edge of Swampy Meadows on the southwestern flanks of Mt. Adams.........May 30, 2005. This species makes an attractive ground cover with early summer flowers which spreads easily via rhizomes. It is most useful for the shaded (or in partial shade) garden amongst ferns and other shade-loving wildflowers where the flowers seem to brightly twinkle like miniature stars.

Characteristics:

Also known as western coolwort, foam flower is an attractive perennial with leafy stems from 15-40 cm high and numerous basal leaves. The stems and leaves are puberulent to hirsute and glandular. The single or clustered stems are erect or spreading. The leaves are like miniature maple leaves. The margins are 3-5 lobed, with toothed edges. The lobes are cut 1/4-1/2 the distance into the middle of the blade above the upper lobes. The basal leaves are up to 12 cm wide and 8 cm long with a heart-shaped base. The upper leaves are similar but smaller with shorter petioles and only 3 lobes. This variety is different from variety trifoliata in that the blade is simple, rather than compound ternate blades of the latter species.

The inflorescence is an open raceme of small white flowers. The white to reddish petals are linear in shape and fringed at the tips and are longer than the calyx lobes. The calyx is 1.5-3 mm long with the lobes about three times longer than the tube. .

Foam flower grows easily in thicker, moist woodland soils and makes an attractive ground cover with tiny white blooms in mid to late spring. The foliage is evergreen, at least west of the Cascade Mts. The latter variety is also less slender in form and more pubescent.


Varieties of Foamflowers Found in the Cascade Mountains of Oregon and Washington:

Foamflower, Foam Flower: Tiarella trifoliata var. laciniata - Basal and stem leaves have 3 leaflets. Each leaflet is cleft more than 1/2 the way into the middle. Flowers white, tiny, in a loose panicle.

Trefoil False Mitrewort, Trefoil Foamflower: Tiarella trifoliata var. trifoliata - Basal and stem leaves have 3 leaflets. Each leaflet is cleft less than 1/2 the way into the middle. Flowers white, tiny, in a loose panicle.

Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata) - Basal and stem leaves simple, maple-leaf shaped with several lobes. Flowers white, tiny, in a loose panicle.


Habitat:

The foam flower may be found in moist shady woods and along stream banks.


Range:

The foam flower may be found from southern Alaska south through the Cascade and Olympic Mts. to Santa Cruz County, CA. It may be found eastward to Alberta and south to western Montana, northern Idaho, and northeast Oregon.


Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata)

Foamflower (var. unifoliata) as seen at a spring near Helispot #122 near the junction of the School Canyon and Little Badger Creek Trails, Badger Creek Wilderness...........June 14, 2014.

Close-up of the inflorescence of Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata)

The photo above shows a close-up of the flowers of collwort foamflower as photographed along the eastern edge of Swampy Meadows on the southwestern flanks of Mt. Adams.........May 30, 2005.

Basal leaf of Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata)

A basal leaf of coolwort foamflower as seen along the Lewis River Trail #31 between Curly Creek Falls and Bolt Camp Shelter, Gifford Pinchot National Forest.........May 3, 2015.

Stem leaf of Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata)

The photo above shows the simple, palmately-lobed stem leaf of coolwort foamflower as seen in meadows immediatelynorth of Hellroaring Creek adjacent to the Island Springs Trail at the southeastern corner of Mt. Adams........July 17, 2005. The stem leaves of this variety may be occasionally trifoliate, but all of its leaves are more typically simple and shallowly to deeply 3-5 lobed.

Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata)

The photo above shows the upper stem leaf and flowers of coolwort foamflower as photographed along the eastern edge of Swampy Meadows on the southwestern flanks of Mt. Adams.........August 6, 2005.

Developing fruits of Coolwort, Foamflower, Foam Flower, One-leaf Foamflower: Tiarella trifoliata var. unifoliata (Synonyms: Tiarella trifoliata ssp. unifoliata, Tiarella unifoliata)

The photo above shows a close-up of the developing fruits of coolwort foamflower as photographed along the eastern edge of Swampy Meadows on the southwestern flanks of Mt. Adams........August 6, 2005.

Paul Slichter