Robert geranium is a weedy annual or biennial with several to many more or less hairy stems spreading to ascending 10-50 cm from the base. The long petiolate leaves are pinnately lobed to dissected, with the lowest measuring from 5-15 cm long. The blades are 3-5 cm wide with the 3-5 lobed to dissected leaflets having short stalks or sessile.
The peduncles are 2-flowered. The sepals are 6-9 mm long and covered with soft hairs with bristles at their tips. The pink to red-purple petals are 8-13 mm long with rounded tips with some white and darker purplish markings. The style column measures 15-20 mm long with the beak measuring 6-7 mm.
Robert geranium may be found in moist forest soils that have been disturbed, especially along roadsides, paths, waste areas and logging landings. A prolific self-seeder (which blooms most of the year west of the Cascade Mts.), it also spreads fairly readily into the adjacent undisturbed forest.
A Eurasian species, has been introduced to western Oregon and Washington.
In the Columbia River Gorge it is commonly found between the elevations of 100'-500' from the Sandy River east to near Cascade Locks in Oregon and Stevenson in Washington.