256 RELATIVE LENGTH OF THE STAMENS, 
two bundles, the stamens are termed diadelphous, as in the Pea 
(fig. 552), Milkwort (fig. 515), and Fumitory ; in which case the 
number of filaments in each bundle may be equal as in the Milk- 
wort (fig. 515) and Fumitory ; or unequal as in the Sweet Pea 
(fig. 552), where there are ten stamens, the filaments of nine of 
them being united to form one bundle, while the other filament 
remains free. When the stamens are united by their filaments 
into three bundles, they are triadelphous, as in most species 
of St. John’s Wort (jig. 554) ; and when in more than three, 
polyadelphous, as in the Orange (fig. 553). The term polyadel- 
phous is applied by many botanists, in all cases, where there are 
more than two bundles of stamens ; it was used in this latter 
sense by Linnzus. 
The union of the filaments in the above cases may either 
take place more or less completely, and thus form a tube of 
varying heights, as in the Mallow (jig. 549) and Wood Sorrel 
Fig. 552. Diadelphous stamens of the Sweet Pea (Lathyrus odoratus), sur- 
rounding the simplepistil. There are ten stamens, nine of which are united 
and one free. Fig. 553. Flower of the Orange divested of its corolla, 
to show the polyadelphous stamens. 
(fig. 550) ; or the union may only take place at the base, as in 
the Tamarix gallica (fig. 506). The bundle or bundles, again, 
may be either unbranched, as in the Mallow (fig. 549); or 
branched, as in the Milkwort (fig. 515) and Castor-oil Plant 
(fig. 555). When the union takes place so as to form a tube or 
column, the term androphore has been applied to such a column, 
as in the Mallow (fig. 549) and Wood Sorrel (fig. 550). 
4. Relative Length.—There are two separate subjects to be 
treated of here, namely, Ist, the relative length of the stamens 
with respect to the corolla; and 2nd, their length with respect 
to each other. In the first place, when the stamens are shorter 
than the tube of the corolla so as to be enclosed within it, as 
in the Forget-me-not (fig. 511), they are said to be meluded ; 
and when the stamens are longer than the tube of the corolla so 
as to extend beyond it, as in the Valerians (jigs. 495 and 556), 
they are exserted or protruding. 
