[The Geraniums of the Columbia R. Gorge]

Robert Geranium, Herb Robert, Stinky Bob

Geranium robertianum

Flower of Herb Robert, Robert Geranium, Stinky Bob: Geranium robertianum

A close-up of the flower of Robert geranium as seen along the Angels Rest Trail in the Columbia River Gorge.................May 18, 2009.

Characteristics:

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.


Habitat:

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.


Range:

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.


Upper stem and inflorescence of Herb Robert, Robert Geranium, Stinky Bob: Geranium robertianum

The densely hairy stem and calyx of Robert geranium as seen along the Angels Rest Trail in the Columbia River Gorge.................May 18, 2009.

Herb Robert, Robert Geranium, Stinky Bob: Geranium robertianum

Robert geranium growing along the Angels Rest Trail in the Columbia River Gorge where it is a pesky weed, blooming and seeding all year except during icy or snow weather in the winter. Photographed May 18, 2009.

Paul Slichter