Invasive Species of the Month: Iceplant (Carpobrotus edulis)
Iceplant is a perennial in the Aizoaceae family, native to South Africa and grows in sandy areas on the coast from Eureka to Baja. This succulently leaved plant is overwhelming and carpets the land. I’ve seen outcompete giant Coreopsis and beach spectacle pod. Iceplant competes for nutrients, water, light and space. In very dry places they have long straggling woody stems. The pink or yellow flowers are beautiful and peak in early summer. The leaves root in the soil at the nodes and reproduces by seed. Seeds that passes through an animals gut germinates better.
Iceplant may be pulled and removed–which is the case at Piedras Blancas lighthouse, with spectacular results from the emerged native plant seedbank. Iceplant may be sprayed and the dead matter makes an excellent mulch for native plantings. Frost also kills Iceplant.
According to Cal-IPC iceplant was brought to California in the early 1900’s for stabilizing soil along railroad tracks. It was planted along freeways by Cal Trans until the 1970’s. Now it provides job security for weed warriors.
– Mark Skinner
Carpobrotus edulis or Carpobrotus chilense?
These two species are very similar, and the Jepson descriptions do not fully cover the overlap of features. Generally C. chilense has smaller magenta flowers (3-5 cm diameter) compared to 8-10 cm for C. edulis, which favors yellow flowers, but there is color ‘crossover’. The flower of C. edulis is pedicelled and C. chilense is sessile. The fruit of C. edulis is triangular in cross section, that of C. chilense more rounded and softer.
The photograph above shows a massive carpet of Carpobrotus at Shark Inlet. The bench in the foreground used to be pickleweed marsh until the Paso Robles earthquake caused the sand dunes to press down into the mudflat, squishing the edge of the flat above the high tide line and enabling the iceplant invasion.
– David Chipping