[Rockcresses: The Genera Arabis, Boechera and Turritis in the Cascade Mountains 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
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.
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.
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Little leaf rockcress observed along the ridgeline of Monte Cristo, Gifford Pinchot National Forest......June 18, 2021.
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.
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.
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Little-leaf rock cress from the Lower Deschutes River, south of Sherar's Bridge.....March
22, 1997.
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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