The specific epithet coulteri commemorates Thomas Coulter, an Irish botanist and explorer.

[3] This herbaceous perennial[4] may exceed 2 m (7 ft) in height, its stem growing from a network of rhizomes.

The gray-green, waxy-textured leaves are each divided into a few lance-shaped lobes, the blades growing up to 20 centimeters (7.8 in) long.

[6] This plant bears the largest flowers of any species native to California, rivaled only by Hibiscus lasiocarpos.

[8] In cultivation in the UK, Romneya coulteri and the cultivar 'White Cloud'[9] have gained the Royal Horticultural Society's Award of Garden Merit.