[Avens: The Genus Geum East of the Cascade Mountains of Oregon and Washington]

Bigleaf Avens, Largeleaf Avens, Large-leaf Avens, Large-leaved Avens, Oregon Avens

Geum macrophyllum var. macrophyllum

Synonym: Geum macrophyllum ssp. macrophyllum

The photo above shows a close-up of the flowers of large-leaved avens subtended by one to several simple, ternately lobed leaves which may be directly below the inflorescence on large-leaved avens.

Characteristics:

Large-leaf avens is a perennial with several basal leaves in a rosette and erect or ascending stems with several leaflets. The stems may rise from 30-70 cm in height. The leaves are compound pinnate or cleft into the middle vein with 9-23 irregularly shaped leaflets or lobes, the largest being the terminal one. The basal leaves may be as much as 30 cm long and the margins are toothed. 2-5 leaves may be found on the stems. These are compound ternate (3 leaflets) with irregularly toothed margins.

The inflorescence is an asymmetrical cyme of several flowers. The 5 green sepals are reflexed downward, each approximately 4-5 mm long. The 5 petals are a medium yellow (not shiny as with buttercups)and 4-6 mm long. The green, maturing fruits look like rounded pincushions with many "pins" poking out.

Varieties of Large-leaf Avens:

var. macrophyllum -

var. perincisum -

Habitat:

Large-leaf avens is found in moist woods or meadows, or along streams from the sea level to subalpine habitats.

Range:

Large-leaf avens may be found from Alaska south to Baja California and Mexico, and east in Canada to Nova Scotia.

This photo shows a pinnately lobed leaf of large-leaved avens. Note the broad terminal lobe which is typically the largest with this species. The terminal lobe of the variety macrophyllum is shallowly round lobed as seen above, while that of the variety perincisum is cleft 1/3-1/2 the length with the lobes in turn more deeply and coarsely toothed.

Paul Slichter