The Palmetto Plant

by Barry Shedrow

The name palmetto is derived from the Spanish palmito or ‘little palm tree’. Palmettoes are herbaceous (non-woody) and evergreen, and are distinguished by their large, fan-shaped compound leaves (fronds) arranged at the top of an unbranched stem. They are a hardy plant, resistant to fire and hurricanes and able to survive freezing winters, hot summers, droughts, salt- laden winds, and standing brackish water. Palmetto plants are members of the palm family (Arecaceae) and belong to a group of grass and grass-like flowering plants called monocots. Common monocots include grass, bamboo, sugar cane, lilies, and grains such as rice, wheat and corn.

 There are several significant differences between palmetto plants and woody plants (e.g., oaks, dogwoods, and pines): (a) the trunk, limbs, and branches of woody plants are strong but relatively inflexible. Woody plants possess a specialized layer of cells called the vascular cambium which is responsible for producing woody tissue. Palmetto plants lack vascular cambium cells and, therefore, do not produce woody tissue. The interior or pith of a palmetto stem consists of a sponge-like material which is softer than wood and very flexible. Because palmetto plants lack the structural strength of wood, they are typically shorter in height than woody trees and their stems possess no lateral limbs; (b) woody plants possess the ability to quarantine damaged or diseased tissue from healthy tissue. This ability enhances a plant’s survivability. Palmetto plants do not possess the capacity to quarantine damaged or diseased tissue. This deficiency could potentially compromise a plant’s long-term viability; and (c) the vascular cambium in woody plants replaces older, aging cells with new cells, as evidenced by the annual growth rings observed in tree trunks, limbs and roots. Because palmetto plants do not possess a vascular cambium, there is no replacement of aging or dead cells. Once a palmetto plant cell is created, it exists for the entirety of the plant’s lifespan unless damaged or destroyed.

 Palmetto plants are common on the Coastal Plain of the southeastern United States. Three species of palmetto plants are native to Seabrook Island: the Sabal palmetto (Sabal palmetto), the Dwarf palmetto (Sabal minor), and the Saw palmetto (Serenoa repens). On the island, all three plants are used in commercial and residential landscapes and can be found growing naturally in undisturbed maritime forest such as SIPOA green spaces.

 The Sabal palmetto (Figure 1), also known as the cabbage palm, cabbage palmetto, sabal palm, Carolinapalmetto,bluepalmetto,Garfield’stree,andswampcabbage,livesinmaritimeforests, onbarrierislands,hammockswithinsaltandbrackishwatermarshes,andontheedgeofponds. This palmetto is unlike other palmetto plants in that its main stem or ‘trunk’ grows vertically upward rather than horizontal and close to the ground. Although most palmetto plants are typically shorter in height than most woody trees, the Sabal palmetto is an exception because it can grow to an average height of 30 to 40 feet, with some specimens growing as tall as 90 feet. Most plants in the Sabal genus don’t produce a large canopy and provide moderate shade at best.

It is believed that the Sabal palmetto can live for as many as 200 to 300 years. The plant’s fruit, which is fleshy and small in diameter at maturity, is eaten or dispersed by birds and other wildlife (e.g., robins, pileated woodpeckers, crows, raccoons). Humans also eat the mature fruit, as well as the apical meristem (growing point at the tip of the main stem or trunk) of the palm. The apical meristem is said to taste similar to artichoke or cabbage, hence the name ‘cabbage palmetto’.

 The Sabal palmetto has been a symbol of pride and liberty in South Carolina since colonial times. During the Revolutionary War, Colonel William Moultrie constructed a fort on Sullivan’s Island made of palmetto palm logs laid over sand walls to protect Charleston and its harbor from the British. In June of 1776, the British fleet attacked the fort, but was repulsed by Moultrie and his men. Moultrie’s ‘secret weapon’ was the Sabal palmetto. A cross-section of the interior of a sabal palmetto stem (or trunk) looks like a porous sponge with multiple bundles of vascular (i.e., conductive) tissue scattered throughout. This spongy material is softer than wood and provides the plant’s stem with remarkable flexibility. That is why a palmetto plant, when buffeted by hurricane force winds, is able to bend and absorb the punishment without breaking. The main reason the British failed in their attack is because their cannonballs either bounced off of or were ‘absorbed’ by the palmetto logs. After the battle, the Sabal palmetto became a symbol of Moultrie’s heroic defense and was subsequently added to the state seal in 1777. In January 1861, the Sabal palmetto was added to the state flag shortly after the South Carolina legislature voted to secede from the union.

 The states of Florida and South Carolina have both designated the Sabal palmetto as their state tree. However, many botanists argue that the Sabal palmetto is not really a tree. The scientific definition of a tree is a long-lived woody plant that has a single erect stem (or trunk) that is at leastthreeinchesindiameter4.5feetabovethegroundandreachesamatureheightofatleast 13 feet. A tree is also defined as having lateral limbs some distance above the ground and possessingadefinitivecrownorcanopyofbranchesandleaves.Otherthanhavingasingleerect stem of sufficient height and thickness, the Sabal palmetto does not possess the other characteristics of a tree. The additional fact that the Sabal palmetto is a monocot (i.e., closely related to grasses and grains), further strengthens the case that the Sabel palmetto does not qualify as a tree.

Figure 1 Sabal Palmetto

The Dwarf palmetto (Figure 2), also known as the bush palmetto, dwarf blue palmetto, and bluestem palmetto, is a ground-hugging palm than can grow to an average height of three feet, with some specimens growing as tall as ten feet. The plant usually lives to be over 100 years old. The dwarf palmetto has no stems, the leaves arise from an underground rootstock. The plant inhabits maritime forests, lowlands, swamps, floodplains and river terraces. Wildlife use the plant for cover and nesting purposes. The berry-like fruit is eaten by raccoon, fox, white tailed deer, and water birds. The large succulent leaf buds and root are edible by humans if properly prepared. The Dwarf palmetto is drought tolerant and thought to be moderately deer- resistant. The plant is also one of the most frost and cold hardy palm species in North America.

 The Saw palmetto (Figure 3) is a small shrublike palm that grows to a maximum height of ten to twelve feet and spreads four to 10 feed wide. The plant grows in clumps or dense thickets in sandy coastal areas and as undergrowth in pine woods or hardwood hammocks. It is a hardy, slow- growing, long-living plant. Some specimens in Florida are thought to be 500 to 700 years old. Erect stems are rarely produced. Lush, green, ‘saw toothed’ leaves fan out from a thorny petiole, hence, the name ‘saw palmetto’. The plant produces berries which, historically, were used by the Seminole Indians as food and to ease urinary and reproductive problems. Today, the berries are used to produce a dietary supplement which is promoted as a remedy to increase testosterone levels, improve prostate health, enhance urinary track function, reduce inflammation, treat migraines, and prevent hair loss. However, clinical evidence regarding the product’s medical efficacy is inconclusive.

 Palmetto plants have many uses. Long before the first permanent English settlement was established in the Province of Carolina, native Americans living along the coast relied upon these plants as a food source, to thatch dwellings, weave baskets, and for traditional medicine. Today, palmetto plants are primarily used as ornamentals in residential, commercial, and urban landscaping. Palmetto fronds have proven to be a versatile material as they are used for roof thatching, furniture, handicrafts (e.g., baskets, hats, and mats), mulch for landscaping, and feed for livestock. Saw palmetto extract is used for medicinal purposes and selected palmetto fruits, stems, and roots are edible by humans. While palmetto plants do provide food, cover, and nesting sites for a variety of wildlife, they are not as environmentally beneficial as woody trees. Palmettoes (and palms in general) possess narrow leaves and small canopies. As such, they produce minimal shade and do little to reduce the surrounding air temperature during hot, sunny days. Because of their limited foliage, palmettoes have a reduced level of photosynthetic activity. They consequently absorb and sequester less carbon dioxide, generate less oxygen, and remove fewer airborne particulates from the atmosphere than trees with more expansive canopies (e.g., hardwoods, conifers).

There are many non-native palm plants found on Seabrook Island. While a few of these plants may have been introduced by wildlife, most of them were brought in by humans for landscaping purposes. A few of the more common non-native palm species on Seabrook include the Mexican fan palm (Washingtonia robusta), Canary Island date palm (Phoenix canariensis), and the Pindo palm (Butia capitata). See Figures 4, 5, and 6, respectively. Next time you’re out for a walk or bike ride, take the time to notice the multitude of palm plants on the island. To help you distinguish palmettoes from the other palm species, look for the following characteristics: (a) trunk orientation - most palmetto plant stems grow out at a slight angle, at or near the ground’s surface, while palm trunks grow vertically upward. The Saban palmetto is an exception to this rule; and (b) shape of leaves - palmetto leaves are fan-shaped while palm leaves are generally pinnate or feather-shaped.