I’ve become extremely familiar with Serenoa repens (PDF), or saw palmetto, through my adventures around Florida. Saw palmetto grows in every Florida county; I think it’s unarguably one of the symbols of Floridian vegetation.
Endemic to the southeastern United States, saw palmetto’s range almost perfectly overlaps with the state of Florida. The range does extend further into the coastal plains spanning from Louisiana to South Carolina (e.g., Daniel’s photo was from coastal Georgia). In much of Florida’s pine and scrubby flatwoods, it thrives as an understory plant growing to just over head height. Stems can be completely or partially underground. Rarely are the stems completely erect, but some plants have been reported as reaching 6 to 7.5 m (20-25 ft.) in height when growing as trees instead of the typical shrub growth form.
Saw palmettos are fan palms, meaning that their evergreen leaves are palmately lobed in the shape of a fan. Compare this to the pinnately-compound leaves (like a feather) of many other palm species. The petioles of Serenoa repens are covered in sharp spines that are the source its common name (I had wrongly first assumed the name was in reference to the shape and pointiness of the leaves resembling a saw blade). The fruits are large fleshy drupes that are readily consumed by animals ranging from insects to mammals; apparently, it is a favourite of black bears.
Previously regarded as an obstacle to agriculture by settlers in the southeast, extensive efforts were made to eradicate saw palmetto from the landscape. This proved difficult, so special methods were designed specifically for this eradication. Simply burning it was ineffective, as saw palmetto’s exceptional fire tolerance and regrowth are necessary traits for plants to endure the (former) frequent fire regimes of Florida. Serenoa repens sprouts quickly from its roots and rhizomes after fire. To mimic natural processes, controlled burns of saw palmetto have recently become a regular occurrence in Florida, making landscapes of charred saw palmetto a common sight. See my photo from 11 years ago that depicts post-burn plants! Incidentally, the photo also demonstrates the repens, or creeping, part of the name.
In recent decades, the economic value of saw palmetto is being re-recognized. Indigenous peoples of the Florida area are known to have eaten, traded, and made medicinal / construction use of saw palmetto for centuries prior to European contact. With the notable decline in populations of these peoples post-contact with European settlers (see link below regarding the Timucua people), human use of saw palmetto also declined. One modern (and somewhat recent) use is in landscaping as a native species, as it is noted as being drought- and insect-resistant with little need for fertilizer. It is far superior to use nursery stock, as plants do not transplant well from the wild. Another “use” is the production of an extract from the treatment of prostate cancer; however, Wikipedia’s section on saw palmetto emphasizes that the treatment is ineffective–perhaps at best a placebo effect from the extract (citations provided).
Saw-palmetto: an Ecologically and Economically Important Native Palm is an exceptional additional resource on ethnobotanical, ecological, and economical topics.
Saw palmetto is the sole species of the monotypic Serenoa, whose name honors the late American botanist Sereno Watson. I also found it intriguing to learn that the indigenous peoples’ use of saw palmetto in thatching gave rise to the name Kanapaha, which describes a small area of Florida’s Alachua County that I’m very familiar with (including Lake Kanapaha). The old book, A Provisional Gazetteer of Florida Place-Names of Indian Derivation (page 67), suggests that the Timucua people’s words “cani” (palmetto leaves) and “paha” (house), were combined in the naming of Kanapaha. Worth a mention as well are the Kanapaha Botanical Gardens, which I remember fondly for their impressive bamboo collections.