Heart-leaved Bittercress, Large Mountain Bittercress, Lyall's Bittercress: Cardamine cordifolia var. lyallii (Synonym: Cardamine lyallii)

Close-up of the inflorescence of large mountain bittercress as seen in Upper Naneum Meadows, Wenatchee National Forest......July 24, 2009.

Large mountain bittercress is a perennial wildflower of wet places. It is erect in habit with stems from 20-50 cm high arising from slender rhizomes from 2-2.5 mm thick. The lower stems range from glabrous to fairly densely haired with short, spreading and simple hairs. The long-petioled, simple, basal leaves are orbicular to ovate shape. They measure 3-7 cm long and 3-7 cm wide with heart-shaped bases and shallow lobed margins. The petioles are typically 2-5 times longer than the blades. The more numerous stem leaves are similar to those at the base but have slightly shorter petioles. The surfaces of all the leaves are glabrous to sparsely haired.

The inflorescence is a few-flowered raceme of white flowers. The spreading to ascending pedicels are 10-20 mm long and the glabrous sepals measure 3-4 mm long. The petals are spatulate-obovate in shape and measure 7-12 mm long. The stamens are slightly longer than the sepals. The fruits are straight, ascending siliques from 2-3.5 cm long and 1.5-4 mm wide.

Large mountain bittercress is a plant of wet places at middle elevations including seeps and streams and moist alpine meadows.

Large mountain bittercress may be found across much of the western United States and Canada.

Large mountain bittercress as seen in a small stream in Upper Naneum Meadows, Wenatchee National Forest........July 24, 2009.

Large mountain bittercress blooming enmasse at a spring along Reecer Creek Road, Wenatchee National Forest........July 6, 2012.

Large mountain bittercress as seen at left in small streams that cross the North Fork Catherine Creek Trail #1905, Eagle Cap Wilderness.......June 12, 2018. The photo at right shows large mountain bittercress in First Swale Creek near the Swale Creek trailhead for the Fremont National Recreation Trail, Fremont-Winema National Forest......June 28, 2019.

Large mountain bittercress with maturing fruits as seen at a creek crossing along the Lick Creek Trail #231, Hells Canyon National Recreation Area.......August 11, 2018.

Large mountain bittercress observed at a small stream crossing of the Hanan Trail #142, Fremont-Winema National Forest.......June 17, 2020.

Basal leaves of large mountain bittercress as seen at left along a stream crossing Forest Service Road #3521, Wenatchee National Forest........July 8, 2012. The photo at right shows large mountain bittercress with maturing fruits along South Fork Crooked Creek about 300 meters uphill from the South Fork Crooked Creek Trailhead, Fremont-Winema National Forest.......August 2, 2020.