[Rockcresses: The Genera Arabis and Boechera East of the Cascade Mts. of Oregon and Washington]

Lemmon's Rockcress

Boechera lemmonii

Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii

Lemmon's Rockcress: Boechera lemmonii (Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii) - Lemmon's Rockcress: Boechera lemmonii (Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii) - Lemmon's Rockcress: Boechera lemmonii (Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii) - Inflorescence of Lemmon's Rockcress: Boechera lemmonii (Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii)

What appears to be Lemmon's rockcress as seen around the old lookout site atop Lookout Mountain, Ochoco National Forest......May 26, 2018.

Characteristics:

Lemmon's rockcress is tufted perennial wildflower with several simple (or occasionally branched) stems which are spreading to mostly erect, rising 5-20 cm high. Many short, sterile leafy shoots may also be seen. Plants are largely glabrous but may also be densely covered with much-branched hairs. The basal leaves are found in a basal rosette. They are oblanceolate to oblanceolate-obovate in shape tapering to short petioles. The leaves are 1.5-2.5 cm long and 3-5 mm wide and have entire to occasionally few-toothed margins. The blades are covered with dense, gray, felt-like hairs which are much-branched in a treelike pattern. The stem leaves are oblong to lanceolate, sessile with heart-shaped bases, and 0.5-2 cm long. The herbage of the leaves varies from glabrous to covered with minute, felt-like hairs.

The inflorescence is a 3-10 flowered raceme. The pedicels measure 2-6 mm long and the glabrous to softly haired, purple sepals are 2.5-3.5 mm long. The rose-purple petals measure 4.5-7 mm long. The pedicels are short and glabrous. The fruits are glabrous siliques which are ascending to spreading. The siliques are often turned to one side and measure 3.5-6 cm long and 1.5-3.5 mm wide. The pods vary from straight to slightly arched.


Habitat:

Lemmon's rockcress is found on cliffs, talus slopes and in alpine meadows in the mountains.


Range:

Lemmon's rockcress may be found from British Columbia south through the Cascade and Olympic Mts. to California and east in the mountains to Montana and Colorado.


Stem leaves of Lemmon's Rockcress: Boechera lemmonii (Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii) - Fruits of Lemmon's Rockcress: Boechera lemmonii (Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii) - Fruit of Lemmon's Rockcress: Boechera lemmonii (Synonyms: Arabis lemmonii, Arabis lemmonii var. lemmonii)

What appears to be Lemmon's rockcress as seen around the old lookout site atop Lookout Mountain, Ochoco National Forest......June 25, 2017.

Paul Slichter