|
 Columnea
is found from southern Mexico to Bolivia, eastward to Amapá Brazil, and
several species can be found on the Caribbean islands. Regardless of the
exact geographic region the species are found in, Columnea requires a
humid tropical climate where temperatures never reach freezing, or even
close to freezing, and humidity remains at a relatively high level year
round. Species of Columnea are not found in seasonally dry forests,
nor do most species occur at higher elevations in the mountains of Central
and South America, although mid-elevations seem ideal.
When found, the plants tend to be widely dispersed with relatively few
individuals per population. This may be somewhat of an artifact of finding
the plants. Since most species are epiphytes, meaning that they grow on the
trunks and branches of trees to be able to get more light than is normally
available in the rain forest understory, it is often difficult to see the
plants unless they are growing on lower branches, have dropped corollas onto
the forest floor, or are found in branches that have fallen or uprooted
trees. (It is important to emphasize that epiphytes use their host trees
only for a space to grow on, they are not parasites and do not tap into the
water or nutrient supply of the host tree.) Since most plant collectors do
not regularly climb each tree, it may be that the populations of Columnea
species are much greater than what we see from the ground below.
Researchers are beginning to study tropical forest canopies and the
diversity of life that is found there, so hopefully in years to come we will
have a better view of the true population density of Columnea
species. |
