|
Sisymbrium
altissimum (Jim Hill Mustard) Brassicaceae (Mustard Family) Semi-desert, foothills. Disturbed areas.
Spring, summer. This native of Europe has spread aggressively throughout the United States. It germinates early in the season, grows rapidly, and has a very effective seed dispersal system: when it dries, it breaks away from the ground at the base of the plant and tumbles along with the wind scattering its seeds. It has all the traits necessary for easy and widespread dispersal and growth. Sisymbrium altissimum commonly grows to three feet (as pictured here) and can reach nearly five feet. It branches in a maze of stems, produces numerous flowers, and quickly goes to seed. The dried plant is buff colored and very stiff. Linnaeus named both this genus and species in 1753. "Sisymbrium" is a name given by the Greeks to some Mustard plant several thousand years ago. "Altissimum" is Latin for "very tall". Jim Hill was a railroad owner and this non-native species is thought to have been spread across the United States along the railroad. |
|
|
Sisymbrium
altissimum (Jim
Hill Mustard) Brassicaceae (Mustard Family) Semi-desert, foothills. Disturbed areas.
Spring, summer. Two-to-three inch long seed pods (on the right side of the photograph) grow very rapidly. |
|
|
Sisymbrium
altissimum (Jim
Hill Mustard) Brassicaceae (Mustard Family) Semi-desert, foothills. Disturbed areas.
Spring, summer. Lower leaves are deeply cut and saw-toothed; upper leaves are cut as deeply but are not saw-toothed. |
Range map © John Kartesz,
County Color Key
|
Range map for Sisymbrium altissimum |
Species present in state and native
Species present in state and exotic
Species not present in state
Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Eradicated
Questionable presence