SAPRUPHYTIU AND 51mpiuilC VEGETATION. 51 
its nourishment solely from the air, and propagates itself chietly by 
the detached strands of its thread-like stems entwined and fastened on 
the limbs and branches of the trees. Epidendron conopseum, a hand- 
some orchid, inhabits large magnolias and hoary live oaks in the 
deepest recesses of the same swampy hammock lands, with numerous 
roots closely fastened to the bark of the largest limbs of these trees. 
Polypodium polypodioides (P. incanum Sw.) and Polypodium vulgare 
are frequent inhabitants of trees. They are, however, found to grow 
also upon shaded rocks and prostrate trunks. 
SAPROPHYTIC AND SYMBIOTIC PLANT ASSOCIATIONS. 
Saprophytes are colorless plants which, as far as those belonging to 
the phanerogams are concerned, live upon the débris of the vegetable 
world, deriving their nourishment from the organic matter resulting 
from its decay. The largest number of saprophytes belong to the 
fleshy fungi and some of these live upon decaying animal matter. 
Being destitute of chlorophyll, their vascular system less developed, 
without breathing pores, their leaves reduced to mere scales, these 
plants are unable to elaborate the constituents needed for nutri- 
tion or to change carbonic acid from the air into assimilated food mate- 
rial. The number of seed-bearing saprophytes occurring in Alabama 
is small, and widely dispersed through the deep, shady forest, as 
Apteria Corallorhiza, and Hexalectris of the orchid family, and in 
grassy, damp swales Burmannias. Hemisaprophytes are green per- 
ennial herbs of the ordinary structure and habits, which for their 
nutrition are only partially and to varying degrees dependent upon 
organic matter. Some live in humid, peaty soils, mostly in the open, 
for example, some of our club mosses (Lycopodium carolinianum, L. 
cernuum) and a number of orchids (Limodorum, Pogonia, Habenuaria 
spp.), while others can exist only in a humid soil, rich in vegetable 
matter, under cover of the forest. 
Symbiots are pale, almost colorless, plants, of waxy appearance, in 
their organization similar to the saprophytes, and have been until 
recently regarded as truly parasitic in their mode of living. It has, 
however, been found that they do not subsist on decomposed vegetable 
matter, nor are they root parasites. They are true symbiots, being 
in their existence closely bound up with that of another plant which 
contributes to their necessities, but is equally benefited hy this con- 
nection; Monotropa and Hypopitys, of the Indian pipe family, belong 
to this group. Immediately after their germination the rootlets of 
these plants are infested by the vegetative threads or spawn (mycelium) 
of a fungus which, as the plant develops, fastens itself upon every 
root, finally enveloping the rootstock with a thick film, the higher 
plant drawing its nourishment solely from the elaborated food of the 
fungus. 
