[ Alders: The Genus Alnus in the Cascade Mountains of Oregon and Washington]

Gray Alder, Mountain Alder, Thinleaf Alder

Alnus incana ssp. tenuifolia

Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis

Dorsal leaf surface of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis) - Ventral leaf surface of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis)

Close-up view of the upper leaf surface (left) and lower leaf surface (right) of mountain alder as seen from seeps along the Canyon Mountain Trail #218, Strawberry Mountain Wilderness........August 19, 2011.

Leaf of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis) - Leaf bud of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis)

Close-up views of the upper leaf surface and a leaf bud of mountain alder as seen from the shoreline of the Deschutes River in the eastern Columbia River Gorge.........September 29, 2007.

Close-up of the ventral leaf surface of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis) - Ventral leaf surface of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis)

Close-up views of the lower leaf surface of mountain alder as seen from the shoreline of the Deschutes River in the eastern Columbia River Gorge.........September 29, 2007.

Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis) - Leaves and stem of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis)

Mountain alder growing in a sedge meadow along Summit Creek where it crosses Forest Service Road 1647, Malheur National Forest........August 4, 2011.

Leaves of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis) - Lower leaf surface of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis)

Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis) - Leaves and catkins of Gray Alder, Mountain Alder, Thinleaf Alder: Alnus incana ssp. tenuifolia (Synonyms: Alnus incana var. occidentalis, Alnus incana var. virescens, Alnus occidentalis, Alnus xpupusii, Alnus rugosa, Alnus rugosa var. occidentalis, Alnus tenuifolia, Alnus tenuifolia var. occidentalis)

Additional photos of mountain alder growing along Forest Service Road #16 at Big Creek in Logan Valley, Malheur National Forest.........August 20, 2011.
Paul Slichter