BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Serenoa repens | Saw-Palmetto 



GENERAL BOTANICAL CHARACTERISTICS : 
Saw-palmetto usually grows as a small shrub with creeping, horizontal,
many-branched stems.  Occasionally it grows as a small tree with erect
or oblique stems.  As a shrub, it grows to a height of 2 to 7 feet
(0.6-2.1 m).  As a tree, it may reach 20 to 25 feet (6.0-7.5 m).  In its
procumbent form, saw-palmetto branches form a tangled mass, with the
root crown projecting above to support the foliage.  The stem systems
run parallel to the soil surface, eventually branching beneath the
substrate to form rhizomes.

Saw-palmetto leaves are fan-shaped, evergreen and about 3 feet (1 m)
wide.  The petioles are armed with sharp spines, giving saw-palmetto its
common name.  The white, perfect flowers are borne on stalked panicles
that grow from the leaf axils.  The fruit is a fleshy, elipsoid drupe,
which is green or yellow before ripening but becomes bluish or black as
it matures [10,15,26,32].


RAUNKIAER LIFE FORM : 
   Undisturbed State: Phanerophyte (nanophanerophyte)
   Undisturbed State: Phanerophyte (microphanerophyte)
   Burned or Clipped State: Cryptophyte (geophyte)


REGENERATION PROCESSES : 
Vegetative:  Saw-palmetto sprouts from horizontal stems and rhizomes.
 
Sexual:  Saw-palmetto flowers are insect pollinated.  Extensive wildlife
use of saw-palmetto fruit suggests that its seeds are animal dispersed.
The fruit endocarp and seed coat are impermeable to oxygen.  Germination
may be delayed 4 to 6 months while these tissues deteriorate [19].  The
soil characteristics required for germination are unknown.

Seedling growth and early development are slow.  Establishment requires
2 to 6 years.  Flooding prevents establishment on wet sites, and
saturated soils retard seedling root development during the summer rainy
season.  Seedlings are vulnerable to competition, drought, and fire
[19].

In the nursery, saw-palmetto may be propagated by seed.  Ripe fruit can
be collected by hand-picking or by cutting the fruit-bearing panicle,
and seeds extracted with a macerator.  Commercial sources of
saw-palmetto seeds are often available.  Seeds with the micropyle cap
removed will germinate in 11 days; those with the micropyle cap intact
may require 45 to 60 days.  Dried seeds average 1,080 per pound
(2,376/kg) [32].


SITE CHARACTERISTICS : 
Saw palmetto grows in a humid, subtropical to warm-temperate climate
[19].  Within its range, the average annual rainfall is 39 to 64 inches
(100-163 cm).  The average maximum and minimum temperatures range from
97 to 25 degrees F (36 to minus 4 deg C) [41].

Saw palmetto usually grows on dry, very well-drained soils [2,30], and
avoids swamps and poorly drained river terraces [10].  Preferred soils
are "sterile" [30] and have very little mineral or organic content, as
typified by fine quartose sands [5].  Soil descriptions are not
ablsolute.  Saw palmetto may also grow on peaty [40] and poorly drained
sites [15].

Saw-palmetto is a common understory shrub of Southern pine flatwoods,
growing on the Miami rock ridge pinelands, the dry pineland portions of
Big Cypress National Preserve, and commercial plantations [9,35,40].
Elsewhere, it is a codominanant in hardwood- and conifer-dominated scrub
communities [4,8,26,37].  In the Everglades region, saw-palmetto is the
most common understory shrub in high hammocks and forms a characteristic
ring around cypress (Taxodium spp.) heads and burnt-over tree islands.
[11,31,37,40].  Strand, dry prairies, and southern oak (Quercus
spp.)-pine (Pinus spp.) types indicate other sites where saw-palmetto
might be common [8,35].

Common overstory associates include slash pine (Pinus elliottii), south
Florida slash pine (P. elliottii var. densa), pond pine (P. serotina),
longleaf pine (P. palustris), sand pine (P. clausa), loblolly pine (P.
taeda), and cabbage palmetto (Sabel palmetto).  Understory associates
include gallberry (Ilex glabra), scrub live oak (Quercus virginiana var.
geminata), scrub oak (Q. chapmanii), myrtle oak (Q. myrtlifolia),
shrubby rosemary (Ceratiola ericoides), scrub palmetto (Sabel etonia),
scrub mint (Conradina grandiflora), blazing star (Liatris tenuifolia),
pawpaw (Asimina reticulata), scrub clover (Petalostemon feayi), ground
blueberry (Vaccinuim myrsinites), and dodder (Cassytha filiformis)
[4,21,30,41].


SUCCESSIONAL STATUS : 
A common understory species, saw-palmetto is shade tolerent and grows in
both sunny and shaded habitats [10].  It is a prominent member of
several Southern fire-climax communities and is a frequent invader of
very dry [40] or frequently burned [37] habitats.


SEASONAL DEVELOPMENT : 
Saw-palmetto blooms between April and July [10,19,32].  Maximum spadix
initiation begins after the danger of frost is past and may be
stimulated by rising temperatures.  The fruits ripen in September and
October.  Maximum saw-palmetto growth occurs during the summer rainy
season, achieving 80 percent of annual production between April and
October [8,14,32].

Related categories for Species: Serenoa repens | Saw-Palmetto