[Endangered / Red-Listed]
The Coastal Scouler’s Catchfly, Silene scouleri spp. Grandis, is a hairy perennial in the Pink Family of flowering plants. It is named after the sticky hairs on its leaves that can trap small insects which try to steal nectar without pollinating the flowers. It is a Red-listed, Endangered species. This species is distinctive for its greenish-white to purplish striped flowers clustered in a narrow spike-like arrangement. The slender pale green leaves are hairy and grow in a rosette of basal leaves that are up to 20 cm long with paired opposite leaves gradually reducing in size up the stem. The whole plant can be 15-80 cm tall and grows erect. It is most likely insect pollinated. The fruit is a dark egg-shaped capsule containing numerous small greyish brown pimply seeds which ripen in September or October and drop from the plants in November.
Found from Southwestern BC on three small islands and northern Washington with main range in southern Oregon and northern California to San Francisco Bay. Closely growing invasive species include Bladder, White Cockle and Rose Campion.
The Coastal Scouler’s Catchfly grows along seashores in dry meadows and rocky bluffs. It is largely found within 30 m of the shoreline or within Garry Oak meadows at higher elevations. It grows only in full sun in soils that dry out in the summer but remain wet through the winter. Flowering occurs in late August to early September, but summer drought can limit flowering and seed set.
This plant prefers exposed, hot, dry, rugged gravelly soils right close to the shores or in traditional open meadows. Each plant that is trampled or grazed or disturbed by humans degrades the population, which is numbered at less than 350 plants in all of Canada.
Habitat loss due to urban development is the main reason for this species endangered status. The discontinuance of controlled burning has limited the habitat for this species by changing the soil strata and allowing invasive species to overwhelm natural pockets of mineralized soil. Other factors including heavy encroachment of invasive grasses and shrubs into rare meadows, trampling, grazing and pollution tax this species’ population growth and recovery. Habitat fragmentation has severely impacted the fecundity of this genetically distinct subspecies.
Information for Landowners:
Removing invasive species from seashore and low elevation meadows is a key action that landowners can undertake themselves. Protecting these rare meadows and bluffs from development and grazing pressure will help this species to recover. Discontinuing use of herbicides and careful stewardship of these rare, exposed shoreline and Garry Oak ecosystems is critical to the survival of all endangered species on Salt Spring Island.
At the Conservancy:
We regularly monitor known sites and protect them through a conservation covenant and stewardship partnerships.