95 
natural Family of Plants called Composite. 
reconciles the opposite statements of Koenig and Roxburgh; for 
I find that at the time of flowering the envelope of each floret is, 
as Roxburgh has figured it, distinct from the ovarium, with which, 
however, in a more advanced stage its tube becomes firmly united; 
a fact that sufficiently accounts for Koenig's description. 
There is here, therefore, a nearer approach to a true perian- 
thium than in the involucrum of Lagasca; but the expansion of 
the flowers being, as in that genus, from centre to circumference 
of the capitulum, I consider the envelope of Ccesulia as unques¬ 
tionably an involucrum, and the genus consequently belonging to 
Polygamia segregata. 
I may here remark, that the name Polygamia segregata, invented 
by Linneus for those genera of Composite with densely aggre¬ 
gate capitula, is calculated to give an erroneous idea of the nature 
of the structure ; the opposite term Polygamia congregata being, 
according to the view now taken, obviously more proper for those 
genera, at least, whose involucra contain several flowers. It is 
not unlikely, indeed, that Linneus himself was aware of the true 
nature of the inflorescence of these genera; but the term Polyga¬ 
mia congregata would not have suited the artificial arrangement 
which he adopted in his subdivisions of the class, nor his includ¬ 
ing in it the order il Jonosramia; for with this order the single 
flowered genera of Polygamia segregata must then have been 
confounded. 
It is a curious circumstance, that the order of expansion in 
Composite does not depend on the number of flowers actually 
existing, but on the effort, if I may so term it, made to produce 
them, manifested by the presence of an involucrum or common 
calyx, which is in some cases reduced to a single flower. The 
fact at the same time contributes to prove, that the whole na¬ 
tural class is formed on that plan of dense aggregation of flowers, 
for 
