18 WINDOW AND PARLOR GARDENING 
essential. The stamen consists of f/ament and anther. In the 
anther numerous infinitely small cells are developed which are 
called by a collective name, pollen. These, when transmitted 
to the stigma, emit slender threads which penetrate the ovary 
and the rudimentary seeds, which thereby, in some mysterious 
way, get power to develop into seeds and plants. 
The floral envelope consists generally of two distinct parts : 
One inner brightly colored whorl of leaves called petals, and 
one outer green whorl called sepals. The number of sepals 
and petals is generally the same. In some species the petals 
are joined together and form a tubular, bell-shaped, or labiate 
corolla. In other families the petals are entirely separate, as 
also the sepals. As to the shape of the gamopetalous corolla, 
that is, a corolla in which the petals are joined together, 
it is wheel-shaped, as in the Tomato, salver-shaped in Phlox, 
funnel-shaped in the Morning-glory, bell-shaped in the Hare- 
bell, and tubular in the now common so-called Cigar-plant, 
and in the common Heaths. ‘There are also irregular shapes 
of this type, as the ringent or labiate corolla of the Snap- 
dragon. 
The many-petalled corolla is often similar in shape to many 
one-petalled flowers. A special form is the cruciform corolla 
of the Wallflower and the papilionaceous corolla of most plants 
of the pea-family. Flowers of the lily family have generally 
two whorls of floral leaves, three in each and almost similar in 
shape and color. Some flowers are ligulate or tongue-shaped 
as in most plants belonging to the aster family. ‘The ‘‘ flower’”’ 
of a Chrysanthemum is not a single flower, but a collection 
or Aead of numerous flowers with a monopetalous strap-shaped 
corolla. At the same time the central flowers, in most species 
of Chrysanthemums, Asters, and their allies are always tubular. 
