Leaves of rosaceae species often have complex patterns of division; those of geum macrophyllum
are pinnately divided into two to six pairs of lateral leaflets, closely spaced, and a much bigger terminal leaflet, reniform in shape. The terminal leaflet is partly divided into two side lobes and a larger terminal lobe. All leaflets have irregularly toothed edges, pinnate veins and hairy surfaces.
The inflorescence is an open, branched cluster of between 3 and 16 flowers. Flowers stalks are densely covered by long hairs. The five sepals are green, bent backwards. The five petals are yellow, obovate to round in shape, generally non-overlapping, and just less than a quarter of an inch long. At the center are a ring of yellow stamens around a group of greenish pistils.Var macrophyllum
has glandular flower stalks and less divided leaves, and is found in coastal areas, below 1,000 feet, while var perincisum
has has non glandular flower stalks and more divided leaves; this is a widespread, higher elevation variety, inhabiting areas above 3,000 feet.