ESSENTIAL OEGANS — STAMENS. 



219 



Pea ; in this case the bundles may be equal or unequal. It frequently 

 happens, especially in Papilionaceous flowers, that out of ten stamens 

 nine are united by their filaments, while one (the posterior one) is free. 

 When the filaments are united ia three or more bundles, the stamens 

 are triadelphous (rjs/S, three), as in Hypericum segyptiacum (fig. 347), 

 or polyadelphous (toXiis, many), as in Luhea paniculata (fig. 348, 1), or 

 in Eicinus communis (fig. 349, 1). These staminal bundles may be sup- 

 posed to be a compound stamen divided, or they may be looked upon as 

 resembling digitately-divided leaves. When there are three stamens in 

 a bundle we may conceive the bundle as representing a leaf, with two 

 stipules united at its base. In Lauracese there are perfect stamens, 

 each having at the base of the filament two abortive stamens or stami- 

 nodes (fig. 357), which may be analogous to stipules. The union of the 

 filaments takes place sometimes at the base only, as in Tamarix gallica 

 (fig. 343); at other times it extends throughout their whole length, so 



Fig. 348, 1. 



Fig. 348, 2. 



Fig. 849, 2. Pig. 349, 1. 



that the bundles assume a columnar form. In certain cases, the co- 

 hesion extends to near the apex, forming what Mirbel calls an andro- 

 phore (avrig, male or stamen, pogew, I bear), or a column which 

 divides into terminal branches, each bearing an anther (347, / e). 

 Occasionally some filaments are united higher up than others, and 

 thus a kind of compound branching is produced (fig. 349, 2). In 

 Pancratium, the filaments are united by a membrane, which may be 

 considered as corresponding to the crown of Narcissus. 



Filaments sometimes are united with the pistil, forming a 

 columna or column, as i^ Stylidium, Asclepiadacese, Eafilesia, and 



Fig. 348, 1. Flower of Luhea paniculata. cccc, SegmentB of calyx, pp. Petals, e e, 

 Stamens grouped in bundles, which alternate with the petals, s. Stigma, composed of five 

 parts, indicating the union of five carpels. 2. One of the staminal bundlesmagnifled, showing 

 all the filaments united in a single mass at the base, but separating superiorly, fa. The 

 larger internal filaments, each ending in an anther, fs, The shorter outer ones, sterile and 

 abortive. Fig. 349, 1. Male fiower of Bicinus communis, or Castor-oil plant, consisting of 

 a calyx, c, composed of five refiexed sepals, and of stamens, e, united by their filaments sd 

 as to form many bundles, thus being polyadelphous. 2. One of the staminal bundles, /, 

 branching above so as to leave the anthers free and separate. 



