Bulletin 229, Diseases of Citrus in Florida


intervals and absorb nourishment from the tissues of the plant
on which it develops.
 The seed germinates in the soil, but after the plant has grown
up and becomes established, the portion started in the soil be-
comes disconnected, and the nourishment for the plant is there-
after obtained from the host plant or the plant on which it grows.
After becoming established, a luxuriant growth of the parasite
soon develops in the form of tendril-like branches, which rapid-
ly spread over the host plant. When dodder becomes very abun-
dant on a tree, it slowly saps its vitality, weakening it and caus-
ing its growth to be stunted.
 Dodder is not a serious pest and requires but little more at-
tention than ordinary vines. It can be controlled by removing
the vine-like parts from the infested citrus trees and clearing
out the nearby wild vegetation, upon which it probably started.
 CASSYTHA
 Another parasitic, vine-like growth that sometimes occurs on
citrus trees is a species of Cassytha (C. filiformis L.) which is
frequently mistaken for dodder. This plant ranges through
southern Florida and a considerable portion of the tropics, being
most abundant in Florida on the lower East Coast from Merritt's
Island southward. The small, tendril-like branches are pallid
green and leafless, or with minute, scale-like leaves. Cassytha
differs from dodder in that the tendril-like branches are more
wiry and in being perennial. The flowering parts of the vine
are inconspicuous. Cassytha is frequently seen in the sand pine
land, growing over the underbrush and lower branches of trees.
It is a more vigorous grower than dodder and makes a looser,
more open appearance on the tree on which is grows (Fig. 99).
In long neglected cases it may entwine about the entire crown
of the tree, badly stunting it. Control measures are the same as
for dodder.
 SPANISH MOSS AND OTHER AIR PLANTS
 The common gray or so-called Spanish moss (Dendropogon
usneoides (L.) Raf.) frequently becomes a pest in citrus groves,
especially in hammocks where live oak trees occur. It is too well
known to need description. This plant is not a moss but a close
relative of the pineapple. The Spanish moss is an epiphytic
plant, peculiar in that it has no true roots, but derives its nour-
ishment from the air, rain, and dew. It grows not only upon