Growing to over five feet, putting out a long plume of yellow flowers, and swaying in the wind gets you attention.  Place yourself in rocks at the side of the trail and the show is yours.  Flowers are a deep lemon yellow and bloom from the bottom of the stalk upward over a period of many weeks, sometimes months.  The dried stems persist for a year or two.  Stanleya pinnata thrives on selenium rich soils and as a result, crushed stems or leaves may have an unpleasant odor.

Frederick Pursh was the first to name this plant, but he placed it in the Cleome genus, giving it the name of Cleome pinnata in 1814 from a species collected by John Bradbury (1768-1823) "in Upper Louisiana [Territory]".  "Pinnata" is Latin for "feathered", referring to the feather-like, dissected lower leaves.

From a specimen he collected near the Missouri River, Thomas Nuttall realized that the plant was not a Cleome and in his 1818 Genera of North American Plants he designated a new genus, Stanleya (honoring British naturalist Lord Stanley, 13th Earl of Derby).  Nuttall named this species Stanleya pinnatifida.  Nathaniel Britton (1859-1934) renamed the plant Stanleya pinnata in 1889.  It has had several dozen other names since Pursh and Nuttall.  (More biographical information about Stanley.)

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Stanleya pinnata