CONTORTED AND PREMORSE ROOTS. 139 
a variety of the common Radish—which is hence called the 
Turnip-radish, in the common Turnip, and in some other plants. 
When what would be otherwise a napiform root becomes com- 
pressed both at its base and apex so that it has no tapering ex- 
tremity, it is sometimes termed placentiform (fig. 270). It occurs 
in the Sow-bread (Cyclamen ewropxum). 
Some botanists regard the roots of the Radish, the Turnip, 
the Cyclamen, and others, as really enlarged stems. We have, 
however, placed them here, in accordance with the more com- 
monly accepted views of their nature, and on account of 
their importance in Practical Botany. The two next described 
forms of roots are also more properly rhizomes, but it is conve- 
nient to notice them here, and so long as their nature is under- 
stood no confusion can arise. 
line Oe BiG. 272. 
Fig. 271. Contorted root or rhizome of Bistort (Polygonum Bistorta).— 
Fig. 272. Przemorse root or vertical rhizome of the Devil’s-bit Scabious 
(Scabiosa succisa). ; 
Contorted or Twisted Root.—When a tap-root, instead of 
proceeding in a more or less straight direction, becomes twisted, 
as in the Bistort (jig. 271), the root is said to be contorted or 
twisted. Premorse Root.—When the main root ends abruptly, 
so as to present the appearance of having been bitten off, it is 
called abrupt, truncated, or premorse (fig. 272). We have a 
good example of this form of root in the Devil’s-bit Scabious, 
which plant has received its common name from a superstitious 
opinion connected with this peculiar bitten-off appearance of its 
root. 
