[The Rock Cress of the Columbia River Gorge of Oregon and Washington]

Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress

Boechera microphylla

Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla

Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla)

The photo above shows little-leaf rock cress as seen on basalt outcrops along the Deschutes River several miles downstream from Sherar's Bridge..........March 24, 2007.

forked hairs on a leaf of Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla) Photo at right: Arabis microphylla var. microphylla leaf. Note the tiny 3-pronged (trifurcate) hairs covering the leaf.
Characteristics:

1. Pink to purple flowers are 4-petaled (5-8 mm in length).

2. Flowers are located in a tight raceme, or occasionally on the outer half of the stem.

3. Stems are frequently erect, with several thin stem leaves.

4. The basal leaves form a tight central clump, The leaves are long and thin in shape.

5. The seed pods are long thin siliques. In variety microphylla, the siliques usually number less than 6, and these are often recurved or pendent.


Habitat:

Little-leaf rock cress may be found on rocky cliffs and outcrops.


Range:

Little-leaf rock cress may be found from British Columbia south to north central and northeastern Oregon, east to Montana and Wyoming.

In the Columbia River Gorge, it is found between the elevations of 100'-400' from about Cape Horn to about Horsethief Butte.


Ascending pods of Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla)

The photo above shows the erect / ascending fruits of little-leaf rock cress as seen near Sherar's Bridge on the lower Deschutes River.................April 18, 2004.

Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla)

The photo above shows little-leaf rock cress as seen on basalt outcrops along the Deschutes River several miles downstream from Sherar's Bridge...................March 24, 2007. Note the elongating fruits which are flattened side to side but become somewhat sickle-shaped with age.

Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla) - Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla)

Little-leaf rock cress from the Lower Deschutes River, south of Sherar's Bridge.....March 22, 1997.

Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla) - Littleleaf Rockcress, Little-leaf Rock Cress, Small-leaved Rockcress: Boechera microphylla (Synonyms: Arabis microphylla, Arabis microphylla var. macounii, Arabis microphylla var. microphylla, Boechera microphylla var. microphylla)

Several views of little-leaf rockcress from north-facing cliffs several hundred yards south of the eastbound Interstate 84 Rest Area at Memaloose, Columbia River Gorge.........March 31, 2014. The cliffs at this site are further shaded by Oregon white oaks which grow from the base of the cliffs. This site is probably on Memaloose State Park lands.

Paul Slichter