FEVER ROOT. o4 
Pentandria and order Monogynia. Its natural 
affinities place it among the Aggregate of Lin- 
neeus and the Caprifolia of Jussieu. It is charac-(%, eau auth, 
terized by a monopetalous, jice-lobed, unequal co- 7 tad, 
rolla; a calyx as long as the corolla; and a ber- 
ry with three cells and three seeds. The species 
perfoliatum differs from the rest in having its 
leaves connate, and its flowers sessile and whorled. 
The root of this plant is perennial and subdi- 
vided into numerous horizontal branches. The 
stem is erect, hairy, fistulous, round, from one to 
four feet high. The leaves are opposite, the 
pairs crossing each other, connate, ovate, acumi- 
nate, entire, rather flat, abruptly contracted at 
base into a sort of neck, resembling a winged 
petiole. This portion varies in width, as Michaux 
has expressed it, “foliis latius, angustiusve con- 
natis.”” In general it is narrow when the plant is 
in flower, as represented in the figure; and wider 
when itis in fruit. The flowers are axillary, sessile, 
five or six in a whorl, the upper ones generally 
in a single pair. Each axilis furnished with two 
or three linear bractes. The calyx consists of 
five segments which are spreading, oblong-linear 
coloured, unequal, persistent. Corolla tubular, 
curving, of a dull brownish purple, covered with 
minute hairs, its base gibbous, its border open and 
