The hermaphrodite ones are tubular with
5, or rarely 4, equal teeth, and occupy the center of the head. These
are often called the flosculous florets or disk-florets. Those of the
circumference are ligulate and ordinarily unisexual, without stamens. In
many cases they are sterile, having only an imperfect ovary. They are
large and brightly colored and are generally designated as ray-florets.
As instances we may cite the camomile (_Anthemis nobilis_), the wild
camomile (_Matricaria Chamomilla_), [131] the yarrow (_Achillea
Millefolium_), the daisies, the Dahlia and many others. Species occur in
this group of plants from time to time that lack the ray-florets, as in
the tansy (_Tanacetum vulgare_) and some _artemisias_. And the genus of
the marigolds or _Bidens_ is noted for containing both of these types.
The smaller and the three-toothed marigold (_B. cernua_ and _B.
tripartita_) are very common plants of wet soil and swamps, ordinarily
lacking the ray-florets, and in some countries they are very abundant
and wholly constant in this respect, never forming radiate flower-heads.
On the other hand the white-flowered and the purple marigold (_B.
leucantha_ and _B. atropurpurea_) are cultivated species of our gardens,
prized for their showy flower-heads with large white or deeply colored,
nearly black-purple florets.
Pages:
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143