Wildlife - Species

Cabbage Palmetto (Sabal palmetto)

Description

The cabbage palmetto belongs to the palm family (Arecaceace). This branchless evergreen tree grows to a height of 10 m (33 ft) tall. The leaves are up to 1 m (3 ft) across and are divided into filamentous segments with a midrib that is 5-20 cm (2 to 8 in) long. The palm produces several flowering stems (panicles) that bear numerous flowers during the flowering season. Flowers are 4-5 mm long, sessile and perfect (flowers contains male and female reproductive parts). The fruit is fleshy, 8-12 mm in diameter, and purplish at maturity.

Preferred Habitat and Biology

The cabbage palmetto is found in the coastal plain region from North Carolina to Florida. The palm inhabits maritime forests, "islands" within salt and brackish marshes, and the edges of ponds. It is also a commonly planted tree in urban areas throughout South Carolina.

The cabbage palmetto produces flowers during July. The fragrant flowers attract a wide variety of insects, bees, wasps, and ants that carry the pollen from flower to flower. Once pollinated, the flowers begin to develop a one-seed fruit that matures during October and November. Many of the mature fruit are dispersed by birds and mammals that disseminate the seeds throughout their local habitats. Some of the fruit are swept away by sea currents and are transported as far away as the North Carolina shores. Seeds are deposited on beaches, maritime communities and "islands" within coastal marshes. The timing of germination and the percentage of seeds that germinate are influenced by soil temperature, illumination, and salinity. Seed germination begins when the soil temperature exceeds 20°C and continues until the soil temperature exceeds 40°C, reaching a peak within the 27.5°C and 30°C soil temperature range. Only seeds deposited in the shady areas or buried under sand or organic debris will germinate. Over 90% of the seeds deposited on soils with a salinity less than 10 ppt germinate, and the percentage of seeds that germinate drops from 90% to 41% as the soil salinity increases to 15 ppt. The cotyledonary stalk (seedling root) first emerges from the germinated seed, and at 4 cm (1.5 in) long, the stalk becomes the primary root. Next, the leaf emerges and grows toward the soil surface, and once it breaks through the surface, the leaf begins to unfold, growing to a length of about 15 cm (6 in) and width of 1.5 cm (0.6 in) before the first frost. Only one seedling leaf is produced during the first growing season, and the rate of leaf production during subsequent years is not known. Soil salinity level above 15 ppt will cause abnormal root growth (stubby, non-branching primary roots) of seedlings.

Species Significance

The fruit of the palmetto is a favorite food of robins, raccoons, and fish crows. Mockingbirds, myrtle warbler, and pileated woodpecker also eat palmetto fruit. People like to eat the apical meristem (growing point at the tip of the main stem) of the tree because its taste is similar to artichoke and cabbage. During the Revolutionary War, coastal forts were made of palmetto logs. The soft stems would absorb the force of cannon balls and not shatter. Today, the trunks are used in the construction of wharves because the wood is resistant to sea-worm infestations. The cabbage palmetto is also prized as an ornamental tree. Cabbage palmetto is common throughout its range and is the state tree of South Carolina.

References

Brown, K.E. 1976. Ecological studies of the cabbage palm, Sabal palmetto. Principes 20:3-10.

Brown, K.E. 1976. Ecological studies of the cabbage palm, Sabal palmetto. II. Dispersal, predation, and escape of seeds. Principes 20:49-56.

Brown, K.E. 1976. Ecological studies of the cabbage palm, Sabal palmetto. III. Seed germination and seedling establishment. Principes 20:99-115.

Brown, K.E. 1976. Ecological studies of the cabbage palm, Sabal palmetto. IV. Ecology and geographical distribution. Principes 20:149-157.

Martin, A.C., H.S. Zim, and A.L. Nelson. 1951. American wildlife and plants: A guide to wildlife food habits. Dover Publications Inc., New York, NY.

Porcher, R.D. 1995. Wildflowers of the Carolina Lowcountry and lower Pee Dee. University of South Carolina Press, Columbia, SC.

Radford, A.E., H.E. Ahles, and C.R. Bell. 1968. Manual of the vascular flora of the Carolinas. The University of North Carolina Press, Chapel Hill, NC.