**Mesembryanthemum crystallinum L. (Aizoaceae)**

**Common Ice Plant, Crystalline Ice Plant**

**Description**. Annual, often densely branched. Stems 10-65 cm long,
decumbent to prostrate, succulent when young, surface densely papillose,
the papillae rounded, 1-2 mm in diameter. Leaves 1-20 cm cm long,
lowermost leaves cordate, cauline ovate to spatulate, flat, viscid,
papillose, often reddish with age, bases tapered, sometimes petiolate,
sometimes clasping, margins entire to wavy, apices rounded. Flowers
solitary (but often many per plant), 7-10 mm wide, short-pedicellate,
the floral tube campanulate, 6-12 mm long, sepals 5, rounded, often
reddish, petals technically 0 (the many petal-like structures are
staminodia or sterile stamens), 6-8 mm long, white, becoming pink,
ascending to spreading, stamens many, ovary inferior, with 5 locules,
fruit a capsule, 6-11 mm long, oblong. Seeds many, brown, ca. 1 mm long
(Abrams 1944, Munz 1959, Vivrette 1993).

Synonyms: *Gasoul crystallinum* (L.) Rotm., *Cryophytum c*. (L.) N.E.Br.

The closely related *Mesembryanthemum nodiflorum* (slender-leaved ice
plant) differs by having erect stems, linear, somewhat terete leaves,
smaller flowers (4-5 mm wide), with a floral tube 4-5 mm long, and
petals aging yellowish.

**Note**: *Mesembryanthemum crystallinum* has become a model system for
the study of Crassulacean Acid Metabolism (CAM) and its relationship to
salt uptake under saline conditions (e.g., Chu et al. 1990, Cockburn et
al. 1996, Cushman et al. 1990, Edwards et al. 1996, Herppich and
Herppich 1997, Ostrem et al. 1987). It and the related *M. nodiflorum*
are among several species recommended for use in revegetating saline
soils contaminated with petroleum spills in the Middle East
(Hegazy1997). In Australia, *M. nodiflorum* has been deliberately
introduced to stabilize saline waste deposits (Jusaitis and Pillman
1997, Semple and Waterhouse 1994).

**Geographic distribution**. Crystalline ice plant is a native of
southern Africa (Moran 1950, Vivrette 1993) and is widely distributed
and naturalized in Australia, southwestern US (Arizona and California),
Chile, and the Pacific coast of Mexico (Agata et al. 1996, Arnold, T.
and B. de Wet. 1993, Moran 1950, Munz 1959, Vivrette 1993).

Crystalline ice plant was first reported from California ("San Diego"
and "Santa Cruz Island") in 1876 (Brewer et al. 1876). Naturalized
populations occur on all the Channel Islands (Junak et al. 1997),
coastal California from Del Norte County southward to San Diego County,
most counties that include the San Joaquin Valley, and interior southern
California (Anonymous. 1998, Vivrette 1993).

**Ecological distribution**. In southern Africa, both *Mesembryanthemum
crystallinum* and *M. nodiflorum* occur principally on saline soils of
open sites. In California and Mexico, common ice plant occurs in open,
disturbed, saline sites, but is most abundant in irrigated areas with
saline soils (Agata et al. 1996, Munz 1959, Vivrette 1993). On the
Channel Islands, crystalline ice plant is often associated with a
combination of deeply eroded sites, saline substrates, and the absence
of typical soils (Halvorson et al. 1988, Vivrette and Muller, 1977,
Halvorson 1994).

**Reproductive and vegetative biology**. Floral biology has apparently
not been investigated in either species, although most members of
Aizoaceae are open-pollinated by insects (Proctor et al. 1996). Based on
studies in northern Africa and southern California (El-Darier 1992,
El-Ghareeb 1991, Vivrette and Muller 1977), seeds can remain dormant for
many years and young plants often grow quickly after initiation of the
rainy season. Seeds of the related *M. nodiflorum* can remain dormant
for as long as 22 years (Gutterman 1994), but germinate readily with
sufficient rainfall.

Vivrette and Muller (1977) showed that crystalline ice plant sequesters
salts in epidermal papillae during the growing season. Plants also
actively transport salts from the root horizon. As plants die, salts are
released onto the soil surface, which accumulates salts at the surface
and thus inhibits germination of other taxa in the immediate vicinity
during the first rains. Invasion and establishment, at least on Santa
Barbara Island, California, was apparently correlated with disturbance
and severe rabbit grazing of other plants (Dunkle 1950, Philbrick 1972)

**Weed status**. *Mesembryanthemum crystallinum* is not considered a
noxious weed in agricultural or horticultural practice, at least at a
global level (not listed by Holm et al. 1977), nor is it considered a
noxious weed by the State Dept. of Food and Agriculture (Anonymous
1996). It is not listed for the United States in Lorenzi and Jeffery
(1987).

**Microbial pathogens.** No literature was found that reported microbial
pathogens.

**Insect pathogens**. Several weevils (Curculionidae: *Calodemas*,
*Lixus*) have been reported to infest *Mesembryanthemum crystallinum*,
but appreantly do not significantly damage plants or reproductive
structures (Louw 1993).

**Herbicide control.** No literature was found that recommended
herbicides.

**Other control methods.** Mechanical removal of plants has been
reported as an effective method in small infestations (Halvorson et al.
1988, Moss 1994). Halvorson et al. (1988) also reported that mechanical
removal was most effective immediately prior to peak vegetative growth
and flowering, and if followed by tillage and revegetation.

**Literature Cited**

Abrams, L. 1944. Illustrated flora of the Pacific states. Volume 2.
Polygonaceae to Krameriaceae. Stanford University Press, Stanford,
California. 635 pp.

Agata, W, Y. Takeuchi, Y. Fukumoto, M. Toyama, and M. Rarinaga. 1996.
Vegetation of Vizcaino desert: II. Changes of vegetation by distance
from seashore to inland. Science Bulletin of the Faculty of Agriculture
Kyushu University. 50: 153-162.

Anonymous. 1996. Exotic pest plants of greatest ecological concern in
California as of August 1996. California Exotic Pest Plant Council. 8
pp.

Anonymous. 1998. USDA Plants Database. USDA National Plants Data Center,
New Orleans, Louisiana. URL: usda.plants.gov

Arnold, T. and B. de Wet. 1993. Memoir 62. Plants of southern Africa:
names and distribution. National Botanical Institute, Pretoria. 825 pp.

Brewer, W. S. Watson, and A. Gray. 1876. Botany. Volume 1. Geological
Survey of California. University Press, Cambridge, Massachusetts. 1976.
628 pp.

Chapman, A. 1991. Australian plan name index. K-P. Australian Government
Publishing Service, Canberra. 1745-2495.

Chu, C., Z. Dai, M. Ku, and G. Edwards. 1990. Induction of crassulacean
acid metabolism in the facultative halophyte *Mesembryanthemum
crystallinum* by abscisic acid. Plant Physiology. 93: 1253-1260.

Cockburn, W., G. Whitelam, A. Broad, and J. Smith. 1996. The
participation of phytochrome in the signal transduction pathway of salt
stress responses in *Mesembryanthemum crystallinum* L. Journal of
Experimental Botany. 47: 647-653.

Cushman, J., C. Michalowski, and H. Bohnert. 1990. Developmental control
of Crassulacean acid metabolism inducibility by salt stress in the
common ice plant. Plant Physiology. 94: 1137-1142.

Dunkle, M. 1950. Plant ecology of the Channel Islands. Publications,
Allan Hancock Pacific Expedition. 13: 247-386.

Edwards, G., Z. Dai, S. Cheng, and M. Ku. 1996. Factors affecting the
induction of crassulacean acid metabolism in *Mesembryanthemum
crystallinum*. Ecological Studies: analysis and synthesis. 114: 119-134.

El-Ghareeb, R. 1991. Vegetation and soil changes induced by
*Mesembryanthemum crystallinum* L. in a Mediterranean desert ecosystem.
Journal of Arid Environments. 20: 321-330.

El-Darier, S. 1992. Mineral nutrient content and turnover rate of
*Mesembryanthemum crystallinum* in the north-western desert of Egypt.
Journal of Arid Environments. 22: 219- 230.

Gutterman, Y. 1994. Long-term seed position influences on seed
germinability of the desert annual, *Mesembryanthemum nodiflorum* L.
Israel Journal of Plant Sciences. 42: 197-205.

Halvorson, W. D. Fenn, and W. Allardice. 1988. Soils and vegetation of
Santa Barbara Island, Islands National Park, California. USA.
Environmental Management 12: 109-118.

Halvorson, W. 1994. Ecosystem restoration on the California Channel
Islands. pp. 485-490. In Halvorson, W. and G. Maender (eds.) The Fourth
California Islands Symposium: update on the status of resources. Santa
Barbara Museum of Natural History, Santa Barbara, CA. 530 pp.

Hegazy, A. 1997. Plant succession and its optimization on tar-polluted
coasts in the Arabian Gulf region. Environmental Conservation. 24:
149-158.

Herppich, W. and M. Herppich. 1997. Influence of leaf water content on
the C3-CAM transition in *Mesembryanthemum crystallinum*. The New
Phytologist. 136: 425-432.

Junak, S., S. Chaney, R. Philbrick, and R. Clark. 1997. A checklist of
vascular plants of Channel Islands National Park. Southwest Parks and
Monuments Association, Tucson, AZ. 43 pp.

Jusaitis, M and A. Pillman. 1997. Revegetation of waste fly ash lagoons.
I. Plant selection and surface amelioration. Waste Management &
Research. 15: 307-321.

Lorenzi, H. and L. Jeffery. 1987. Weeds of the United States and their
control. Van Nostrand Reinhold Company, New York. 355 pp.

Louw, S. 1993. Breeding populations of *Lixus carinerostris* Boheman and
*Calodemas prolixus* Faust (Coleoptera: Curculionidae) co-existing on
Mesembryanthemaceae. Coleopterists Bulletin. 47: 335-339.

Moran, R. *Mesembryanthemum* in California. Madroño 10: 161-163.

Moss, T. 1994. Ice plant eradication and native landscape restoration.
Proceedings, California Weed Conference. 46: 155-156.

Munz, P. 1959. A flora of California. University of California Press,
Berkeley. 1681 pp.

Ostrem, J., S. Olson, J. Schmitt, and H. Bohnert. 1987. Salt stress
increases the level of translatable mRNA for phosphoenolpyruvate
carboxylase in *Mesembryanthemum crystallinum*. Plant Physiology. 84:
1270-1275.

Philbrick, R. 1972. The plants of Santa Barbara Island, California.
Madroño 21: 329-393.

Proctor, M., P. Yeo, and A. Lack. 1996. The Natural history of
pollination. Timber Press, Portland, Oregon. 479 pp.

Semple, W. and D. Waterhouse. 1994. Performance of halophytes from
semi-arid areas on two saline seepage scalds of the Central Western
Slopes of NSW. Cunninghamia. 3: 595-608.

Vivrette, N. 1973. Mechanism of invasion and dominance of coastal
grassland by *Mesembryanthemum crystallinum* L. Ph.D Dissertation,
University of California, Santa Barbara.

Vivrette, N. and C. Muller. 1977. Mechanisms of invasion and dominance
of coastal grassland by *Mesembryanthemum crystallinum*. Ecological
Monographs 47: 301-318.

Vivrette, N. 1993. *Mesembryanthemum*. p. 129. In Hickman, J. (ed.). The
Jepson manual: Vascular plants of California. University of California
Press, Berkeley. 1400 pp.