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Field Guide
to the
Hardwood Hammock Nature Trail
By Ryan Vogel
Introduction
The FIU Nature Preserve is a managed site, developed to reproduce communities indigenous
to the Florida Everglades. It was first dedicated a Preserve in 1978 by the FIU Administration
and has since achieved various other certifications through the National Wildlife Federation,
the North American Butterfly Association, and Fairchild Tropical Botanic Garden.
The FIU Nature Preserve is home to 248 plant species including 13 threatened species, 9
endangered species, and 4 endemic species, endemic meaning that these species are present
nowhere else in the world but southern Florida. It also provides habitat for approximately 95
species of birds, 45 species of butterflies, 20 species of reptiles and amphibians, and several
small mammals as well.
This field guide is an attempt to present an overview of the major plant species found in a
hardwood hammock community.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
1. Shortleaf Fig (Ficus citrifolia)
Figure 6 – Fruits on long stalks
Figure 7 – Fruit on stalk with mutualistic wasps inside
Although Ficus trees can be seen all throughout Miami-Dade County along roadsides and in
parks, most of the commonly planted Ficus are exotic; there are only two species that are truly
native to southern Florida. One of which is the notorious Strangler Fig (Ficus aurea) and the
other is the Wild Banyan Tree or Shortleaf Fig. The easiest way to tell the two species apart is
by their fruit; F. citrifolia has its fruit on a small stalk or peduncle, as opposed to F. aurea
whose fruits are borne sessile (attached directly to the branch).
The shortleaf fig is an evergreen tree with one solitary trunk unlike its close relative F. aurea
which has a more irregular trunk form, often growing as a vine in its earlier stages. The tree
has alternate, entire leaves that are 5 – 11 cm long and 3.5 – 9 cm wide. The leaves are dark
green, leathery, and smooth. The most significant difference between this tree from the
closely related strangler fig is that the fruits are borne on obviously elongated stalks, not
sessile.
2. Sabal Palm (Sabal palmetto)
Figure 8 – Tree form
Figure 9 – Persistent leaf bases on trunk
Figure 10 – Costapalmate leaf
Figure 11 – Leaf fibrous hairs
Here is the Florida state tree, the Sabal Palm. This is one of the most common palms in
southern Florida due to its ability to grow in very diverse habitats (pine rocklands, hardwood
hammocks, and wet prairie communities). It is one of only 8 native palms in the state of
Florida, and one of only four that exist in the Everglades.
Sabal palms are straight trunked trees which do not grow more than 50cm in diameter or 18m
in height. They have unique costapalmate, fan shaped leaves (1 – 2 m long) which are deeply
divided and conspicuously V-shaped; these are key distinguishing factors in identifying this
species. Each leaf has numerous fibrous threads suspended from the segment margins. The
lead petioles can be up to 2 m long and the trunk will often be covered with these persistent
leaf bases for years to come; however just as often you will see this tree with no persistent leaf
bases, so this is not a great identification factor.
3. Live Oak (Quercus virginiana)
Figure 12 – Stout, wide canopy
Figure 13 – Short trunk and immensely horizontal branches on mature trees
Figure 14 – Revolute, stiff, dark green leaves
Figure 15 – Light brown to black (when mature) acorn
Here is a very typical hammock species, the Live Oak. It is the southernmost reaching oak in
all of the United States, with its range extending well into the Florida Keys.
Although these trees will never grow to be that tall (20 m), they do become very widespread,
bulky individuals as they age. Typically they have a short central trunk, with rough bark, which
divides into several large branches within a few meters from the ground. These trees have
alternate, simple, entire, leathery, and stiff leaves about 2 – 15 cm long and 1 – 5 cm wide.
The leaves are dark green and shiny above and pale gray and tomentose below.
4. Dahoon Holly (Ilex cassine)
Figure 16 – Tree/leaf/fruit growth habit
Figure 17 – Leaf tip often with spines
Figure 18 – Fruit form
5. Ferns
Figure 19 – Brackenfern
Figure 20 – Swamp fern
Figure 21 – Resurrection fern
6. Gumbo Limbo (Bursera simaruba)
Figure 22 – Tree form
Figure 23 – Copper peeling, flaky bark
These are very iconic hammock species that can grow to be quite large when given the time
and the right environment. However, they are usually medium sized deciduous trees growing
to about 20 m in height with a slightly spreading canopy. The copper-colored resinous bark
has the aroma of turpentine and can often be seen flaking off to reveal a brilliant green under
layer. This peeling superficially resembles the skin of a visitor to Miami when they have not
applied sufficient sunscreen, giving it the local name of the “Tourist Tree”.
7. Fire bush (Hamelia patens)
Figure 24 – Leaf/stem/flower color
This is a large evergreen shrub that grows to about 5 m in height and has a wide spread. The
leaves are opposite or whorled with 2 – 7 leaves at each node and interpetiolar stipules at
each node as well. Each leaf is simple, entire, elliptic, 5 – 15 cm long, 2 – 8 cm wide, and the
leaf blades are often reflexed upward from the central vein. The leaves, veins, and petioles
have a reddish tint while the tubular flowers are bright red/orange, which is why it gets its name
Fire bush.
8. Slash Pine (Pinus elliotti) and Coontie (Zamia pumila)
Figure 25 – Tree form with clustered needles
Figure 26 – Bark color and form
Figure 27 – Cone form and needles clustered at branch tip
Southern Florida is home to the last remaining fragments of pine rockland habitat; a highly
endangered and endemic ecosystem that is found nowhere else in the world. A healthy pine
rockland environment has a canopy that is dominated by slash pine (Pinus elliotti), the pines
you see here above you. Due to timbering interests and development, very few large stands of
pine rockland still remains today.
Slash pines are evergreen conifers with long needles (13-30 cm) arranged in fascicles of 2 or
3. The ovulate cones are 7-16 cm long. A mature tree will grow to be 18-30 m in height and
have a trunk diameter of up to 65 cm. Slash pine occurs as far west as Louisiana, as far north
as South Carolina and south throughout Florida, the Keys, and the Caribbean.
Pinelands usually have a very open understory due to high occurrence of fire which eliminates
many understory species except those that are well adapted to fire like the coontie. Coontie is
a small shrub that was at one time an important food crop in southern Florida, which almost led
to the species’ extinction. This plant is a cycad, which means it has special reproductive cones
known as strobili. Cycads are a very old family of plants that have been around since the age
of the dinosaurs.
However, due to the lack of fire here in the Preserve, much of the ecosystem has succeeded
to a tropical hardwood hammock community. Succession is the natural replacement of one
plant community by another, a process that takes place over time with the lack of disturbance.
Figure 28 – Coontie growth habit
Figure 29 – Leaf color and growth habit
Figure 30 – Coontie reproductive strobili
9. Myrsine (Myrsine cubana)
Figure 31 – Growth habit and leaf color
Figure 32 – Cauliflorous flower habit
A plant adapted both to open places and shady hammocks is the myrsine. It is often a pioneer
plant invading recently burned areas. Myrsine is a hardy survivor of fires by means of stump
sprouts. Along the branch, below the leaves, are located clusters of small flowers or black
fruits, which are borne sessile, along the stem. These are found only on the female plants.
You may notice small, dark bumps on the stems of the myrsine. These are lobate lac scale
insects, Paratachardina lobata, native to India and Sri Lanka. These were first documented in
South Florida in 1999, and since then has been found to infest at least 39 different native plant
species. Some more susceptible species include: Cocoplum, Wax Myrtle, Red Bay, Strangler
Fig, Wild Coffee, and of course Myrsine. Currently, research into biological controls is being
conducted in order to eradicate this pest.
10. Red Bay (Persea borbonia)
Figure 33 – Leaf color and growth habit
Figure 34 – Fruit habit
Figure 35 – Lanceolate leaf shape
Red Bay is a common tree in mature hammocks, but they especially like wetter sites, which is
why you can find them growing along the margins of swamp islands in the Everglades. The
leaves are glossy with a pale underside. Red Bay is related to several economically important
food plants such as the avocado, camphor, and cinnamon. Like Bay leaves used in cooking,
the leaves of Red Bay emit a spicy aroma when crushed.
This is an evergreen shrub that grows to be a small tree no larger than 20 m in height. It has
alternate, simple, entire, lanceolate, 2 – 15 cm long and 1.5 – 6 cm wide leaves that when
crushed give off an aromatic fragrance similar to that of the culinary bay leaf. The fruits are
rounded dark blue drupes that get to be 1.2 cm in diameter.
11. Pidgeon Plum (Coccoloba diversifolia)
Figure 36 – Leaf color and habit
12. Solution Hole and Pond Apple (Annona glabra)
Figure 37 – A typical Everglades solution hole
Figure 39 – Leathery, dark green leaves
Figure 38 – Pond apple tree habit
Figure 40 – Fruit resembles commercial apples
Solution holes are formed from detritus or decaying pant material, which in turn lowers the pH
of the water and soil in a particular area. This acidified water/soil is then able to eat away at
the basic limestone rock substrate, developing a hole or depression in the rock.
Pond apple is a common freshwater wetland species found in southern Florida. It really thrives
in wetlands and produces fruits that are similar in shape and size to our commonly cultivated
apples. The fruits have a very bitter taste and begin to turn yellowish when they are ripe.
13. Bitterbush (Picramnia pentandra)
Figure 41 – Shrub growth habit
Figure 42 – Leaf color and form
Bitterbush is a small evergreen tree and typical understory plant; rarely reaching its full
potential of 6m in height. It has alternate pinnately-compound leaves that are 20 - 36 cm long
with 5-9 slender pointed leaflets. During the dry season, the leaves often turn red. The female
plant will produce red berries. It is state-listed as endangered and is endemic to Miami-Dade
County. Each leaflet is entire, ovate, with an acuminate apex, 5 – 10 cm long and 2 – 5 cm
wide.
14. Jamaican Dogwood (Piscidia piscipula)
Figure 43 – Revolute leaves and papery fruit pods
These trees are deciduous, have twisted branches, and thin gray bark. They can grow to
about 15 m tall. They have alternate, oddly-pinnate compound leaves (10 - 23 cm long), each
with 5 - 11 leaflets. Each leaflet is grayish green and 4 - 10 cm long with wavy, often revolute
margins and obvious primary and secondary veins. The fruits are light brown pods, 7.5 - 10
cm long and 2.5 - 3.7 cm wide, each with four papery wings.
15. Wild Tamarind (Lysiloma latisiliquum)
Figure 44 – Leaf habit
Figure 45 – Flower habit
If you look up and to your left you will see a few very large Wild Tamarind trees looming
overhead. In this more open setting, rather than deep inside a hammock, the tree develops a
spreading umbrella-like crown. This characteristic makes them excellent street and shade
trees.
Beneath the lowest pair of leaflets you will find nectar glands which secrete nectar while the
leaves are young. Although, this tree only grows to about 10 or 20 m in height, they are known
to develop a wide canopy spread. The trunk has light gray or whitish bark. With alternate,
bipinnately compound leaves with an overall length from 10 – 18cm long. Each leaf having
between 2 and 4 pairs of pinnae and each of those pinna with 8 – 15 pairs of leaflets. The
miniscule leaflets are 8 - 15 mm long, 3 – 5 mm wide with an elliptic or oblong shape. The
fruits are flat pods, 6 – 10 cm long, 2 – 4 cm wide, and usually remain on the tree throughout
the entire year.
16. West Indian Mahogany (Swietenia mahagoni)
Figure 46 – Compound leaves
Figure 47 – Asymmetrical leaf margins
Although many know Mahogany as a valuable piece of timber, these trees hold an important
ecological role as well. These evergreen trees only establish once a hammock has achieved a
sufficient age and level of maturity.
They grow to about 15 m in height with rough, dark brown, coarsely furrowed bark. Often they
have a buttressed base as well as wide spreading branches. The leaves are alternate and
even-pinnately compound, typically with two to four pairs of leaflets per leaf. Many mahogany
leaflets curve backwards toward the base of the rachis, with one side of each leaflet seeming
slightly shorter than the other. The fruits are very large, conspicuous, upright, egg-shaped
capsules. The fruits split into five parts from the base and rely on the wind to transport their
winged seeds.