BROOM-RAPES, BALANOPHORE, RAFFLESIACE. 183 
sented in fig. 37, is indigenous to Europe and Asia, its area of distribution extending 
from England eastwards to the Himalayas, and from Sweden southwards to Sicily. 
Two species are confined to the East, the Crimea and the Balkans, and another 
Toothwort (Lathrea clandestina), distinguished by large flowers, but slightly 
raised above the earth, extends in western and southern Europe from Flanders over 
France to Spain and Italy. This last has the distinctive feature that the discoid 
suckers developed on its yellow roots, which latter are of the thickness of a quill, 
are as large as lentils and the biggest hitherto discovered on any plant. 
BROOM-RAPES, BALANOPHOREA, RAFFLESIACEAL. 
The fourth series of parasitic Phanerogamia is composed of plants destitute of 
chlorophyll, whose seed contains an amorphous embryo without cotyledons or 
radicle. The seed germinates on the earth, and the embryo grows as a filiform body 
into the ground and there fastens upon the root of a host-plant, penetrates into 
and coalesces with it in growth, forming a tuberous stock, from which, later on, 
flowering stems are projected above the earth. 
To this series belong the Broom-rapes or Orobanchez and the Balanophore:. 
Of the genus Orobanche about 180 species are recognized, which, exhibiting great 
uniformity in floral structure and in their general development, can only be 
distinguished by minute characteristics. The flowering stem growing up from the 
subterranean tuber is, in all the species, rigid, erect, thick, fleshy, and covered at the 
top with dry scales. The open flowers, ringent in shape, are crowded together in a 
terminal spike, and often emit a strong scent like that of pinks or sometimes of 
violets. The colour of the flowers is in one group (Phelypea) mostly blue or violet; 
in the rest it is waxen yellow, yellowish-brown, dark-brown, rose-red, flesh-tint, or 
whitish. Orobanche violacea and O. lutea, both natives of Northern Africa, have 
stems which grow to a height of half a meter and become almost as thick as an arm. 
The best-known species is the Branched Broom-rape (Orobanche ramosa), which is 
parasitic on the roots of hemp and tobacco plants, and is very widely distributed. 
The greatest number of species belong to the East and to Southern Europe. The 
extreme north of America harbours one species which bears a single flower at the 
end of its stem. In all the species the stem projects only partially above the earth. 
The subterranean portion, adherent to the root of a host, is often greatly swollen 
and thickened above the place of attachment; in the case of Striga orobanchoides, 
which is prevalent in the Nile basin, it is irregularly lobed above the host’s root. 
The root of the nutrient plant also is usually somewhat swollen wherever a 
parasitic Orobanche has settled upon it, and sometimes it exhibits an irregular 
outgrowth inclosing the spot whereto the Orobanche is adnate like a cup. Beyond 
the place of attachment of the parasite the root has often the appearance of having 
been bitten off, and this is owing to the fact that the particular piece of root has 
been killed and demolished by the attack of the parasite. From the base of the 
stem, near the point of adhesion to the host, spring short, thick, fleshy fibres, and 
