hemiepiphytes begin their life cycles as epiphytes but
eventually become rooted in the ground. Perhaps
the best- known group of primary hemiepiphytes is
the stranglers (Ficus spp.), members of the fig family
(Moraceae). There are approximately 750 species of
Ficus (figs) throughout the global tropics. Stranglers
germinate in the tree crown from seeds dropped by a
bird or mammal. The seedling’s tendrils grow toward
the tree bole and then grow downward around the bole
anastomosing, or fusing together like a crude mesh (plate
3- 39). The strangler eventually reaches the ground and
establishes its own root system (plate 3- 40). The host
tree often dies and decomposes, leaving the strangler
standing alone. The mortality of the host tree results
from being girdled by the strangler, which prevents the
host’s bole from expanding. Stranglers also may shade
the tree on which they grow, reducing its ability to
photosynthesize. A mature strangler, its host tree having
died and decomposed, is a common sight in tropical
forests (plate 3- 41). The strangler’s trunk is a dense
fusion of what were once separate vines, now making a
single, strong woody labyrinth that successfully supports
a wide canopy, itself now laden with vines.
Secondary hemiepiphytes begin as rooted plants and
eventually become epiphytic climbers. In humid tropical
forests it is common to see boles partially enshrouded
by the wide, thick leaves of climbers (plate 3- 42). The
well- known ornamental arum Monstera deliciosa is
a philodendron that begins life on the ground. Seeds
germinate and send out a tendril toward shade cast by
a nearby tree. The tendril soon grows up the tree trunk,
attaching by aerial roots, and the vine thus moves from
the forest floor to become anchored on a tree (plate
3- 43). As it grows the plant ceases to be rooted in the
ground at all, and its entire root system is invested on
the tree bark. It continues to grow ever upward on its
host tree, often encircling the bole as it proliferates.Epiphytes
Epiphytes are commonly called air plants. As the prefix
epi- implies, these plants live on other plants. They are not
internally parasitic, but they do claim space on a branch
where they set out roots, trap soil and dust particles,
and photosynthesize as canopy residents. Rain forests,
both in the temperate zone (such as the rain forests ofPlate 3- 39. Strangler fig anastomosing,
or forming a connected network, as its
tendrils and branches surround a tree
trunk. Stranglers are hemiepiphytes,
and typically grow down a host tree to
eventually reach the ground. Photo by
John Kricher.
Plate 3- 40. Numerous strangler figs have
engulfed their host tree, which is all but
invisible here. Photo by John Kricher.Plate 3- 41. Strangler figs, such as this
Ficus tree from Panama (with the author
standing at its base), become towering
canopy trees in many tropical lowland
forests. Photo by Diana Churchill.52 chapter 3 rain forest: the realm of the plants