Ice plant, iceplant
Scientific name: Mesembryanthemum crystallinum
Mesembryanthemum crystallinum, ice plant, is native to South Africa. It is a small succulent ground cover that grows in sandy to rocky coastal areas. Botanists have learned much from this plant about mechanisms employed to survive extreme environmental conditions (Ruff, 2006; Winter & Smith, 1996; Cushman, 2001; Cushman & Borland, 2002). While salt absorption causes most plants to wither and die, ice plant is able to accumulate and then release these salts into the surrounding soil (Vivrette & Muller, 1977).
Ice plant is very peculiar in appearance. The plant is covered with bladder-like cells that store water. They glisten in the sun giving it a frosty appearance (see photo). Older leaves redden with age, giving the plant color. It has no true petals. Instead flowers have two rings of white stamens (the male sexual organs) surrounding the female organs (carpels). The outer ring of stamens is flattened and petal-like (see photo) and only the inner ring of stamens is fertile. Modified Petal-like stamens are highly unusual in seed-bearing plants. Plant geneticists are currently investigating the genes responsible for development of these structures.
Ice plant produces red berries with four to five strongly divided sections full of small round seeds (Stephens, 1994; Vivrette, 2006). Mice and other rodents are among the dispersers of these seeds (Randall, 2006), but sailors may have played the largest role in it its spread. Early Sailors used bagged sand to balance ships; these bags were dumped when the ship loaded up with goods and supplies (Randall, 2006). Seeds mixed in the sand then sprouted, colonizing new beaches. Additionally sailors cultivated ice plant to use for treating survey and as potted ornamentals (Vivrette, 2006). Today ice plant is widespread across the globe; it can be found in Australia, Asia, the Americas, Mediterranean Europe, the Atlantic Islands, and North and South America. (Vivrette & Muller, 1977)
It is believed that sailing vessels from the 1500s introduced ice plant to the United States (Vivrette, 2006). Then early European settlers sold and planted it for food. They boiled it for greens and used it fresh as a salty garnish (Ruff, 2005). For a period in mid 20th Century, it was planted along highways to reduce erosion (Randall, 2006). Sadly, this plant has proven to be invasive on the west coast of North America. It invades coastal bluffs and grasslands, out-competing native plants and pasture species. (Vivrette & Muller, 1977; Randall, 2006)
Map: Red area indicates the native range of Mesembryanthemum crystallinum. Known areas of naturalization are not included. Map created by Heather Fara, University of Florida.
Photos: (a) Flower by Gary A. Monroe, USDA-NRCS PLANTS Database (b) Epidermal cell detail by Bernd Krüger, www.bkaussi.de.
Bohnert (2006) Mesembryanthemum. University of Illinois, Urbana-Champaign. Version: 5 Feb 2005. http://www.life.uiuc.edu/bohnert
Cushman (2001) Crassulacean Acid Metabolism. A Plastic Photosynthetic Adaptation to Arid Environments. Plant Physiology 127: 1439-1448.
Cushman & Borland (2002) Induction to Crassulacean acid metabolism by water limitation. Plant Cell & Environment 25: 295-310.
Randall (2006) Mesembryanthemum crystallinum. California Invasive Plant Council, University of California - Davis.
Ruff (2006) Plants of Upper Newport Bay, Orange County California. University of California, Irvine. Version: 30 Jan 2006. mamba.bio.uci.edu/~pjbryant/biodiv
Stephens (1994) HS614: Ice Plant-Mesembryanthemum crystallinum L. Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.
USDA, NRCS. 2005. The PLANTS Database, 3.5. National Plant Data Center, Baton Rouge. Version: 6 Feb 2006.
Vivrette (2006) Mesembryanthemum. Flora of North America 476:76. Version: 6 Feb 2006. www.efloras.org
Vivrette & Muller (1977) Mechanism of Invasion and Dominance of Coastal Grassland by Mesembryanthemum crystallinum Ecological Monographs 47(3):301-318.
Winter & Smith (1996) Crassulacean Acid Metabolism. Springer-Verlag, Berlin Heidelberg, Germany.