Saw Palmetto
Encyclopedia
Serenoa repens, commonly known as saw palmetto, is the sole species
currently classified in the genus
Serenoa. It has been known by a number of synonyms, including Sabal
serrulatum, under which name it still often appears in alternative medicine
. It is a small palm
, normally reaching a height of around 2–4 m (3–6 ft). Its trunk is sprawling, and it grows in clumps or dense thickets in sand
y coastal lands or as undergrowth in pine
woods or hardwood
hammock
s. Erect stems or trunks are rarely produced but are found in some populations. It is endemic to the southeastern
United States
, most commonly along the Atlantic
and Gulf Coastal
plains, but also as far inland as southern Arkansas
. It is a hearty plant; extremely slow growing, and long lived, with some plants, especially in Florida
, possibly being as old as 500-700 years.
Saw palmetto is a fan palm, with the leaves
that have a bare petiole
terminating in a rounded fan of about 20 leaflet
s. The petiole is armed with fine, sharp teeth or spines that give the species its common name. The teeth or spines are easily capable of breaking the skin, and protection should be worn when working around a Saw Palmetto. The leaves are light green inland, and silvery-white in coastal regions. The leaves are 1–2 m in length, the leaflets 50-100 cm long. They are similar to the leaves of the palmettos of genus Sabal
. The flower
s are yellowish-white, about 5 mm across, produced in dense compound panicle
s up to 60 cm long. The fruit
is a large reddish-black drupe
and is an important food source for wildlife and historically for humans. The plant is used as a food plant by the larva
e of some Lepidoptera
species such as Batrachedra decoctor
, which feeds exclusively on the plant. This plant is also edible to human beings, but the more green it is the more bitter tasting it would be.
The generic name honors American botanist
Sereno Watson
.
The fruits of the saw palmetto are highly enriched with fatty acid
s and phytosterol
s, and extracts of the fruits have been the subject of intensive research for the treatment of benign prostatic hyperplasia
(BPH). This extract is also commonly used for other medical conditions, such as baldness
, polycystic ovarian syndrome, and other hyperandrogen conditions, though research on such uses is weak or absent.
Numerous meta-analyses of clinical trials S. repens extract in the treatment of BPH have found it safe and effective for mild-to-moderate BPH compared to placebo, finasteride
, and tamsulosin
Two larger trials found the extract no different from placebo. An updated meta-analysis including these trials found that saw palmetto extract was only superior to placebo for the symptom of nocturia. However, saw palmetto was only compared to finasteride in one study and tamsulosin in two studies. Future clinical trials should focus on comparisons to active treatments and not just placebo.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
currently classified in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Serenoa. It has been known by a number of synonyms, including Sabal
Sabal
Sabal is a genus of New World palms, many of the species being known as palmetto. They are fan palms , with the leaves with a bare petiole terminating in a rounded fan of numerous leaflets; in some of the species, the leaflets are joined for up to half of their length...
serrulatum, under which name it still often appears in alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....
. It is a small palm
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
, normally reaching a height of around 2–4 m (3–6 ft). Its trunk is sprawling, and it grows in clumps or dense thickets in sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
y coastal lands or as undergrowth in pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
woods or hardwood
Hardwood
Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...
hammock
Hammock (ecology)
Hammocks are dense stands of hardwood trees that grow on natural rises of only a few inches higher than surrounding marshland that is otherwise too wet to support them. Hammocks are distinctive in that they are formed gradually over thousands of years rising in a wet area through the deposits of...
s. Erect stems or trunks are rarely produced but are found in some populations. It is endemic to the southeastern
Southeastern United States
The Southeastern United States, colloquially referred to as the Southeast, is the eastern portion of the Southern United States. It is one of the most populous regions in the United States of America....
United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, most commonly along the Atlantic
Atlantic Plain
The Atlantic Plain is one of eight distinct United States physiographic regions. This major division consists of the Continental Shelf and Coastal Plain physiographic provinces. It is the flattest of the U.S. physiographic divisions and stretches over in length from Cape Cod to the Mexican border...
and Gulf Coastal
Gulf Coastal Plain
The Gulf Coastal Plain extends around the Gulf of Mexico in the Southern United States and eastern Mexico.The plain reaches from the western Florida Panhandle, the southwestern two thirds of Alabama, over most of Mississippi, some of western Tennessee and Kentucky, southwest Arkansas, the Florida...
plains, but also as far inland as southern Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
. It is a hearty plant; extremely slow growing, and long lived, with some plants, especially in Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, possibly being as old as 500-700 years.
Saw palmetto is a fan palm, with the leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
that have a bare petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
terminating in a rounded fan of about 20 leaflet
Leaflet
A leaflet in botany is a part of a compound leaf. A leaflet may resemble an entire leaf, but it is not borne on a stem as a leaf is, but rather on a vein of the whole leaf. Compound leaves are common in many plant families...
s. The petiole is armed with fine, sharp teeth or spines that give the species its common name. The teeth or spines are easily capable of breaking the skin, and protection should be worn when working around a Saw Palmetto. The leaves are light green inland, and silvery-white in coastal regions. The leaves are 1–2 m in length, the leaflets 50-100 cm long. They are similar to the leaves of the palmettos of genus Sabal
Sabal
Sabal is a genus of New World palms, many of the species being known as palmetto. They are fan palms , with the leaves with a bare petiole terminating in a rounded fan of numerous leaflets; in some of the species, the leaflets are joined for up to half of their length...
. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are yellowish-white, about 5 mm across, produced in dense compound panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....
s up to 60 cm long. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a large reddish-black drupe
Drupe
In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...
and is an important food source for wildlife and historically for humans. The plant is used as a food plant by the larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e of some Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
species such as Batrachedra decoctor
Batrachedra decoctor
Batrachedra decoctor is a species of moth belonging to the Batrachedridae family. It is native to the southeastern United States especially in northern Florida.-Subspecies:*Batrachedra decoctor decoctor...
, which feeds exclusively on the plant. This plant is also edible to human beings, but the more green it is the more bitter tasting it would be.
The generic name honors American botanist
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
Sereno Watson
Sereno Watson
Sereno Watson was an American botanist.Graduating from Yale in 1847, he drifted through various occupations until, in California, he joined the Clarence King Expedition and eventually became its expedition botanist...
.
Saw palmetto extract
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s and phytosterol
Phytosterol
Phytosterols, which encompass plant sterols and stanols, are steroid compounds similar to cholesterol which occur in plants and vary only in carbon side chains and/or presence or absence of a double bond. Stanols are saturated sterols, having no double bonds in the sterol ring structure. More than...
s, and extracts of the fruits have been the subject of intensive research for the treatment of benign prostatic hyperplasia
Benign prostatic hyperplasia
Benign prostatic hyperplasia also known as benign prostatic hypertrophy , benign enlargement of the prostate , and adenofibromyomatous hyperplasia, refers to the increase in size of the prostate....
(BPH). This extract is also commonly used for other medical conditions, such as baldness
Baldness
Baldness implies partial or complete lack of hair and can be understood as part of the wider topic of "hair thinning". The degree and pattern of baldness can vary greatly, but its most common cause is male and female pattern baldness, also known as androgenic alopecia, alopecia androgenetica or...
, polycystic ovarian syndrome, and other hyperandrogen conditions, though research on such uses is weak or absent.
Numerous meta-analyses of clinical trials S. repens extract in the treatment of BPH have found it safe and effective for mild-to-moderate BPH compared to placebo, finasteride
Finasteride
Finasteride is a synthetic antiandrogen that inhibits type II 5-alpha reductase, the enzyme that converts testosterone to dihydrotestosterone...
, and tamsulosin
Tamsulosin
Tamsulosin is an α1a-selective alpha blocker used in the symptomatic treatment of benign prostatic hyperplasia . Tamsulosin was developed by Yamanouchi Pharmaceuticals and is marketed by various companies under licence, including Boehringer-Ingelheim and CSL...
Two larger trials found the extract no different from placebo. An updated meta-analysis including these trials found that saw palmetto extract was only superior to placebo for the symptom of nocturia. However, saw palmetto was only compared to finasteride in one study and tamsulosin in two studies. Future clinical trials should focus on comparisons to active treatments and not just placebo.
External links
- Serenoa in Flora of North America
- Serenoa repens
- Serenoa repens from Floridata
- Scanpalm - Serenoa repens
- Interactive Distribution Map for Serenoa repens