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Adapting to
life in the scrub...
The plants of the Florida scrub are
especially adapted to life in a harsh environment. In
order to adapt successfully to life in the scrub, plants
must:
- avoid being eaten
- survive occasional fires
- deal with heat and little water
How not to be had for dinner...
Many scrub plants
are adorned with thorns and spines. Many scrub plants are
highly aromatic, containing volatile oils. These
chemicals protect the plants from being eaten. They give
the plant a strong taste and smell (like camphor,
peppermint, or oregano). In some cases these oils simply
make the plant taste bad. In others they are toxic and
could kill the diner. At least one Florida scrub plant
has been shown to have important insecticidal properties.
Others may have medicinal uses. Most have not even been
investigated.
Surviving Fire...
Most scrub plants
resprout from underground stems, rhizomes or roots after
a fire. Others are killed by fire but replace themselves
with seeds already stored in the soil. The sand pine (the
only kind of tree normally found in scrub) retains its
seeds in sealed cones on its branches until it burns to
death.
Dealing with heat and lack of water...
Most scrub plants
do not have long taproots - the water table is too far
below the sandy surface; instead, their roots are massed
near the surface to take advantage of condensation and
Florida's brief afternoon thunderstorms. Because there is
no tree canopy in scrub, temperatures drop rapidly when
the sun goes down and that causes moisture to condense on
the leaves. The moisture then falls in drops right above
the roots.
 Many
scrub plants have waxy-covered or curled leaves to resist
evaporative water loss. Some have hairs (called pubescence) on the
underside of the leaves to resist evaporation by
maintaining high humidity at the surface. These hairs
also increase the surface area for dew to form on. The
needle-like leaves of many scrub plants may reduce
evaporation (which occurs from the leaf underside) during
the daytime, and provide increased surface area for dew
to form on at night. This scrub holly has curled, spiny
leaves that are oriented vertically, the better to direct
water drops to its own roots.
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