The photo at right 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.
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.
Large-leaf avens is found in moist woods or meadows, or along streams from the sea level to subalpine habitats.
Large-leaf avens may be found from Alaska south to Baja California and Mexico, and east in Canada to Nova Scotia.
