Orchids of the Cloud
Forest
The secret orchids of
Cloudbridge
Orchids are plentiful in alongside the trails in the forests of the
Chirripo valley — but they are easy to miss, since
many are tiny, some
live
high in the trees, and they may not be in flower. Here are some
guidelines for identifying the flowers, and a little information about
these beautiful plants.
What
makes an orchid distinctive?
All orchids have 3 petals and 3 sepals (outer segments). One of the
petals, the lower, more attractive one, is modified; it is called the
lip or labellum. In some orchids some of these parts are reduced or
fused. The two lateral sepals of Paphiopedilum are fused, for
example. The petals and lip of Masdevallia are greatly reduced
and the sepals are broadly joined, giving the
flowers a distinctive triangular or tubular shape. There are some
plants which bear flowers greatly resembling orchids in this
arrangement of flower parts.
Orchid organs
To truly identify an orchid as such, one must look at the reproductive
parts, the stigma (female) and the anthers (male). These are separate
in most flowers, but fused in orchids; the structure bearing
reproductive parts is called the column. It sits atop the lip,
as shown in the diagram.
The family
An orchid is a member of the largest and most advanced blooming plant
family. Over 25,000 species have been described, and over 70,000
artificial hybrids have been produced by crossing wild and cultivated
forms.
 Above and below
Many orchids are epiphytes (air plants, growing up in the trees) and
some are terrestrial. Epiphytic orchids are not parasites: the host
tree
is simply a good place to live. They feed off water and dust and
nutrients which accumulate around their roots.
Cloud forests have the biggest
number
of epiphytes, among them orchids. Up to 1500-1700m the number
of epiphytes
increases, then it starts to decrease. At 2000-3000m this forest
resembles
some of the forests in temperate climates. In those places conditions
are
very similar in different spots (on the soil level and on the tree
trunks) and epiphytes often grow on soil or stones. In some place
orchids overwhelm tree trunks and branches.
In these mountain forests, conditions change considerably with
altitude. The higher one gets the smaller the trees get and fewer
species there are. Rainfall quantity at first increases, then
decreases. The maximum falls
on the middle part of the mountain. Temperature decreases the higher
you
get. Vertical gradient changes from 0.4 to 0.7 C for 100 meters. Day
temperature amplitudes are high, whereas seasonal are small. As it gets
more cloudy
humidity increases, but there is less and less light. In mountain
forests
there is always fresh air circulation. Here one finds orchids that
thrive
in cooler conditions – Odontoglossums, Miltonias, Masdevalias,
Oncidiums,
and Dendrobiums.
Orchids
in
Costa Rica
At right is Costa Rica's national flower — the stunning orchid Guaria
Morada, Cattleya Skinneri. Out
of the 1,360 species of orchids that grow in Costa Rica, 386 of them
are
found nowhere else in the world. Almost all of them are epiphytes.
Costa
Rica, in fact, provides much of the world's supply of cultivated
orchids. We encourage observation, and we'd love help with
identification — but please
don't remove
them.
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