The perianth is not changed in double flowers, hence the genus or family
may be often discovered by the calyx, as in Hepatica, Ranunculus, Alcea.
In those flowers, which have many petals, the lowest series of the petals
remains unchanged in respect to number; hence the natural number of the
petals is easily discovered. As in poppies, roses, and Nigella, or devil
in a bulb. Phil. Bot. p. 128.]

[_Iris_. l. 71. Flower de Luce. Three males, one female. Some of the
species have a beautifully freckled flower; the large stigma or head
of the female covers the three males, counterfeiting a petal with its
divisions.]

[_Cupressus_. l. 73. Cypress. One House. The males live in separate
flowers, but on the same plant. The males of some of these plants, which
are in separate flowers from the females, have an elastic membrane; which
disperses their dust to a considerable distance, when the anthers burst
open. This dust, on a fine day, may often be seen like a cloud hanging
round the common nettle. The males and females of all the cone-bearing
plants are in separate flowers, either on the same or on different
plants; they produce resins, and many of them are supposed to supply the
most durable timber: what is called Venice-turpentine is obtained from
the larch by wounding the bark about two feet from the ground, and
catching it as it exsudes; Sandarach is procured from common juniper; and
Incense from a juniper with yellow fruit. The unperishable chests, which
contain the Egyptian mummies, were of Cypress; and the Cedar, with which
black-lead pencils are covered, is not liable to be eaten by worms. See
Miln's Bot. Dict. art. coniferæ. The gates of St. Peter's church at
Rome, which had lasted from the time of Constantine to that of Pope
Eugene the fourth, that is to say eleven hundred years, were of Cypress,