STAMENS. 
69 
more numerous, this is owing to the development of one or 
more additional whorls by dedoublement^ or unlining. Most 
Endogenous plants have either three or six stamens, and the 
number five or ten is most common in Endogenous plants. 
The stamens arise from the receptacle {torus) of the flower, be- 
tween the base of the petals and the pistils. 
77. Stamens are exterior with respect to the pistil, and inte- 
rior with respect to the corolla. They exhibit a variety of 
positions with respect to the pistil. If the stamens are in- 
serted xijpon the pistil, as in umbelliferous plants, they are 
said to be ejpigynous (from upon, and gynia^ pistil) ; if the 
stamens are inserted imder the germ, as in cruciform plants, 
they are said to be hypogynous (from kypo^ under, and gynia^ 
pistil); when the stamens are inserted upon the calyx, and 
thus stand around the germ, as in the rosaceous plants, they 
are said to be perigynous (from peri^ around, and gynia^ pis- 
til). The normal position of stamens is below the pistil. 
is usually either equal, double, or half that of the divisions 
of the corolla; the stamens in such flowers never exceed 
twenty. In polypetalous corollas the number of stamens is 
often greater. When they equal tlie divisions of the corolla, 
they usually alternate with these divisions. When the num- 
ber of stamens is double the divisions of the corolla, half of 
the stamens are usually placed in the intervals of the divisions, 
and the remaining half before each lobe of the corolla, cor- 
responding to the intervals in the divisions of the calyx. If 
any of the stamens are barren, or without anthers, they will 
be found to be those which are placed before the lobes of 
the corolla. Like the other parts of the flower, the stamens are 
modified leaves, resembling them in their structure, and like 
them consisting of cellular and vascular tissue. They appear 
at first as cellular projections, and are arranged in a spiral 
form, unless the normal law be changed by circumstances. 
They have a greater resemblance to petals than to leaves, and 
we often see a gradual transition from petals to stam^ens. 
a. In commencing the analysis of flowers according to the Linnjean system, we 
learned that the number of stamens, their position, relative length, and connectio7i, 
taken either singly or in combination, afford certain and distinctive marks for pm*- 
poses of classification. 
In the first place we find the stamens differing in number, in different plants ; 
Bome plants have but one, some two, and so on, till we come to ten ; when they 
have more than ten, we find the number in the same plant varies, and therefore we 
cannot depend on this circumstance for further classification. 
77. Tosition of the stamens with respect to the pistil — Divisions of monopetalous corollas usually in 
proportion to the number of stamens— Situation of the stamens with respect to the divisions of the 
ooroll I — a. Stamens used for purposes of classification. 
number of the stamens 
