[Wikipedia] Native to South Africa, California Invasive: It is native to South Africa and it is known on other continents as an introduced species and sometimes a noxious weed. It is an invasive species on the Central Coast of California, where it is a minor threat to native coastal vegetation, although not as harmful as other species of invasive iceplant. (link added by Mary Ann Machi)

[Cal-IPC] Habitat, Growth Habits: Conicosia pugioniformis (narrowleaf iceplant) is a succulent perennial (family Aizoaceae) found on dunes, beaches, scrub and grassland along the central coast of California, especially in Santa Barbara and San Luis Obispo counties. Narrowleaf iceplant does not form mats like other invasive iceplants (i.e., Carpobrotus edulis or C. chilensis) so its impacts are less severe. However, it can become locally abundant and crowd out native plants, especially in dune habitats. Narrowleaf iceplant reproduces by seed, and buried root crowns can resprout after aboveground plant matter has been removed. (link added by Mary Ann Machi)