XVI 
OUTLINES OF BOTANY. 
forms a tube round the pistil, or, if the pistil is wanting, occupies the centre of the 
flower. 
diadelphous, when so united into two clusters. The term is more especially ap- 
plied to certain Leguminosce, in which nine stamens are united in a tube slit open on 
the upper side, and a tenth, placed in the slit, is free. In some other plants the sta- 
mens are equally distributed in the two clusters. 
triadelphous , pentadelphous, polyadelphous, when so united into three, five, or 
many clusters. 
syngenesious, when united by their anthers in a ring round the pistil, the filaments 
usually remaining free. 
didynamous , when (usually in a bilabiate flower) there are four stamens in two 
pairs, those of one pair longer than those of the other. 
tetradynamous, when (in Cruciferai) there are six, four of them longer than the 
two others. 
exserted, when longer than the corolla, or even when longer than its tube, if the 
limb be very spreading. 
114. An Anther (109) is 
adnate, when continuous with the filament, the anther-cells appearing to lie their 
whole length along the upper part of the filament. 
innate, when firmly attached by their base to the filament. This is like an adnate 
anther, but rather more distinct from the filament. 
versatile, when attached by their back to the very point of the filament, so as to 
swing loosely. 
115. Anther-cells may be parallel or diverging at a less or greater angle ; or diva- 
ricate, when placed end to end so as to form one straight line. The end of each an- 
ther-cell placed nearest to the other cell is generally called its apex or summit, and 
the other end its base (36) ; but some botanists reverse the sense of these terms. 
116. Anthers have often, on their connectivum or cells, appendages termed bristles 
(set®), spurs, crests, points, glands, etc., according to their appearance. 
117. Authers have occasionally only one cell : this may take place either by the dis- 
appearance of the partition between two closely contiguous cells, when these cells are 
said to be confluent ; or by the abortion or total deficiency of one of the cells, when 
the anther is said to be dimidiate. 
118. Anthers will open or dehisce to let out the pollen, like capsules, in valves, pores, 
or slits. Their dehiscence is introrse , when the opening faces the pistil ; extrorse, 
when towards the circumference of the flower. 
119. Pollen (109) is not always in the form of dust. It is sometimes collected in 
each cell into one or two little wax-like masses. Special terms used in describing these 
masses or other modifications of the pollen will be explained under the Orders where 
they occur. 
§ 11. The Pistil. 
120. The carpels (91) of the Pistil, although they may occasionally assume, rather 
more than stamens, the appearance and colour of leaves, are still more different in 
shape and structure. They are usually sessile ; if stalked, their stalk is called a podo- 
carp. This stalk, upon which eaoh separate carpel is supported above the receptacle, 
must not be confounded with the gynobasis (143), upon which the whole pistil is some- 
times raised. 
121. Each carpel consists of three parts : 
1. The Ovary, or enlarged base, which includes one or more cavities or cells, con- 
taining one or more small bodies called ovules. These are the earliest condition of the 
future seeds. 
2. the Style, proceeding from the summit of the ovary, and supporting — 
3. the Stigma, which is sometimes a point (or punctiform stigma) or small head 
(a capitate stigma) at the top of the style or ovary, sometimes a portion of its surface 
more or less lateral and variously shaped, distinguished by a looser texture, and covered 
with minute protuberances called papillce. 
122. The style is often wanting, and the stigma is then sessile on the ovary, but in 
