PARASITISM IN FLOWERING PLANTS. 
231 
PoLYBRHizAL, I * •'With green leaves or chlorophyll. 
On roots : 
Harveija^ Striga, &c. 
Orohanche, &c. 
Monotrojm ? See. 
/oxjna^ &c. i Rhinantlius, &c. 
Seottia, See. | TJiesium, See. 
Petrosavia. j 
LemioacecB? I 
In the plates accompanying this article are figures, drawn 
partly from nature and partly from various j^ofilished memoirs 
on the subject, of non-clilorophyllous parasites, selected as 
examples of the various modes of attachment above mentioned. 
To illustrate the monobasic condition a species of Filostyles 
(P. cethiopica, Welw.) has been chosen. This genus is placed 
in the Rafflesiacece, an order consisting of some twenty-five 
species, mostly tropical, and contains a few forms, chiefly 
from South America, but some occurring in Asia Minor and in 
Africa. Each plant (see Plate XCIX., figs. 1-4) consists simply 
of a little unisexual flower, surrounded with several rows of 
bracts, and containing in its centre either a column, round the 
head of which is a circle of one-celled anthers (fig. 3), or a 
hemispherical knob, the stigma, below which is situated the 
nnilocular ovary, containing numerous minute ovules attached 
to its sides (fig. 4), and succeeded by a globose fleshy berry. 
These little flower-plants occur in groups sessile and half im- 
mersed on the younger twigs of trees and shrubs, and, so far as 
known, all the species grow on Leguminosse only. They appear 
to originate beneath the bark, little round knobs upon which are 
the first indication of their presence. These increase in size, split 
■open, and allow the contained Filostyles to emerge. The bark 
thus forced up forms a prominent ridge round the parasite, 
and after the latter has fallen off a little cup-shaped cavity 
long remains (see fig. 2). The union of stock and parasite 
is not difficult to rupture, and the latter is readily detached, its 
base not penetrating into the woody structure of the branch. 
In the great species of Fafflesia^ Sapi'ia, and Brugmansia of 
the East Indies, there is, at least in the first, actual vascular 
■connexion, the vessels of the stock passing absolutely into the 
base of the parasite. 
Cytinus Hypocistis (also figured on Plate XCIX., figs. 5-9), 
is another monobasic parasite. This pretty plant is not un- 
■common in the South of Europe and North Africa, growing, 
-as its name implies, on the roots of species of Cistus in the 
spring. The whole plant is brilliant orange-yellow, and con- 
sists of an axis clothed with overlapping scales, and bearing at 
the top a tuft of flowers. These are unisexual, the antheri- 
On stems : 
Loranthus, Sue. 
Fisewn, See. 
On roots f partially parasitic) : 
