SafePlants

Arabis platysperma: Pioneer Rockcress

Arabis platysperma, commonly known as Pioneer Rockcress or Broad-seeded Rockcress, is a perennial herb belonging to the genus Arabis. It is also referred to as Broad seeded rock cress.

Taxonomy and Nomenclature

• Scientific Name: Arabis platysperma A. Gray
• Family: Brassicaceae (Mustard Family)
• Synonyms: Boechera platysperma
• Varieties:
  • Arabis platysperma A. Gray var. platysperma (note: not an active name; see Boechera elkoensis)
  • Arabis platysperma A. Gray var. howellii (S. Watson) Jeps. (Howell's Pioneer Rockcress)

Distribution and Habitat

This species is found in regions such as the Sierra Nevada in California and the Bodie Hills. It has also been observed in the Pioneer Range, Beaverhead National Forest, in Montana, as well as southwest Montana where it is restricted to specific and localized locations.

Morphology and Growth Habit

• Pioneer Rockcress is a perennial herb and can develop into a round-shaped subshrub reaching up to 2 meters in height.

Ecological Role

• Pioneer Rockcress is considered a pioneer species, meaning it is among the first plants to colonize disturbed or newly available habitats.
• The text indicates that it may be hybridizing with the common Pioneer Rockcress, which suggests potential genetic interactions in its environment.

Interactions with Other Organisms

• The text suggests that Pioneer Rockcress and other pioneer species such as groundsel, alpine rockcress, mosses, and lichen play a role in the recolonization of areas after glacial retreat.

Further Information

• Discover Life provides information about the biology, natural history, ecology, identification, and distribution of Arabis platysperma.
• Dave's Garden is mentioned as a community where tips and ideas for gardens, seeds, and plants are shared.
• Jepson Herbarium