52 PLANT LIFE OF ALABAMA. 
PARASITIC PLANT ASSOCIATIONS. 
True parasites are also destitute of chlorophyll, and leafless, but 
they take their nourishment from the living tissues of their host, sub- 
sisting entirely on its elaborated food materials. Three species of 
this class of parasites which foist themselves upon the roots of their 
hosts (root. parasites) occur in the Carolinian zone of Alabama, and 
are also frequently found in other parts of temperate North America, 
all belonging to the family of broom rapes (Orobanchaceae), namely: 
Conopholis americana. Thalesia uniflora. 
Leptamnium (Epiphegus) virginianum. 
Of the parasites which fasten themselves upon the stems of their 
host, 6 are found in Alabama, all belonging to the dodders or love vines 
(Cuscuta). These plants at the start root in the ground, but upon 
springing up, when they meet a plant suitable for a host they wind 
themselves around its stem and at places of close contact send haus- 
toria through its bark to the wood, and, the cells of the two uniting, 
the parasite draws its food from the plant attacked. Thus firmly 
established, the part of the stem of the parasite connecting it with the 
ground dies, and it depends henceforth entirely for its nourishment 
on its host. The chlorophyll-bearing shrubby parasites of trees are 
represented by a single species, the American mistletoe (Phoradendron 
flavesvens). 
The so-called hemiparasites—green herbs which fasten themselves 
by their lateral rootlets upon the roots of their host—are only partly 
dependent upon assimilated food material. These half-parasites belong 
mostly to the figwort family, examples being Canadian lousewort 
(Pedicularis canadensis), painted cup (Castilleja canadensis), and sev- 
eral Gerardias. The number of plants subsisting in this way has not 
been ascertained, but outside of the Scrophulariaceae, Comandra and 
Darbya are also supposed to be hemi-parasites. 
INSECTIVOROUS PLANTS. 
A class of these plants inhabit the bogs of peat mosses and the damp 
flat open pine barrens of the Coast plain, consisting of sarracenias 
(Sarracenia), sundews (Drosera), butterworts (Pinguicula); and others, 
viz, the bladderworts (Utricularia), inhabit stagnant or still-flowing 
waters of shallow pools, ponds, lakes, and streams, floating upon the 
surface of the water or immersed. It is evident that by the faculty of 
appropriating animal substances for their nourishment, nature has 
provided these plants with an additional supply of nitrogenous food 
which the sterile soil, extremely deficient in the elements required for 
plant nutrition, does not contain. In order that they may get hold of 
the animals serving them for food they are endowed with peculiar 
appliances of a highly specialized character, as, for example, the 
