16 THE STORY OF (PLANT Lire 
They are called definite as contrasted with the 
indefinite racemose types. Examples are St. John’s 
Wort, Rockrose, etc. 
Some others are of mixed type, the Labiates being 
racemose in primary branching, the lateral ones 
dichasial or cymose. 
The flower is built up on a receptacle or torus, or 
thalamus, which bears the stamens and carpels, which 
are the most important in the reproduction of the 
plant and take part in the pollination and fertilisa- 
tion which precede seed-formation. 
Around these are arranged the protective and 
attractive perianth. This is made up of an outer 
whorl termed the calyx, consisting of a number of 
segments called sepals. The inner whorl consists of 
the generally coloured corolla with petals varying 
also in number. In some plants the perianth is 
wanting, and the plant is termed apetalous. The 
different types and their arrangement are described 
under the headings for each chapter. 
When the stamens and carpels are upon the same 
plant it is hermaphrodite or bisexual; when on 
different plants the inflorescence is unisexual, the 
male plants being staminate, the female pistillate. 
In the former type the female flowers are usually 
above the male. 
When the stamens and carpels are found in the 
same hermaphrodite flower it is monoclinous, when 
in separate plants the flower is diclinous. When 
male and female plants are both borne on the same 
