PAET IV. CLASSIFICATION. 



plants. The stamens of each flower may be coherent into one or 

 more bundles. The arrangement becomes complicated when the 

 filaments are at the same time coherent and branched as in the 

 Malvaceae. When the filaments are all coherent into a single 

 bundle (e.g. Malvacese), they are said to be monaddphous ; when 

 in two bundles (e.g. some Papilionese, Fumariacese), they are 

 diadelphous ; when in several bundles (e.g. Hypericacese), they are 

 polyadelphous. In the Compositse (e.g. Sunflower and Thistle), 

 though the filaments are free, the anthers become coherent or 

 syngenesious. When the stamens are quite free from each other 

 they are said to be polyandrous. 



Besides these varieties of cohe- 

 sion, adhesion frequently occurs ; 

 that is the filaments adhere to 

 other portions of the flower, par- 

 ticularly of the perianth, so that 

 they or when they are very 

 short, the anthers appear to be 

 inserted not upon the axis of the 

 flower, but upon the leaves of the 

 perianth (epipetolout or epiphyl- 

 lous) : this condition is most fre- 

 quently present when the petals 

 themselves are connate and form 

 a tubular corolla, e.g. Primula. 

 The adhesion of the stamens to 

 the carpels is of rarer occurrence 

 (e.g. Orchidacese, Aristolochia) ; 

 the flower is then termed gynan- 

 drous. 



In many flowers it happens that certain filaments, occupying a 

 definite position with regard to the other parts of the flower, are 

 longer than ths others ; thus, of the six stamens of the Cruciferse 

 (e.g. Wallflower), four are much longer than the other two ; of the 

 four stamens of the Labiatae, (e.g. Lamium), two are longer than 

 the other two. In the former case the stamens are said to be te- 

 tntdynamous, in the latter didynamous. 



Stamens which bear no anthers are termed stanii nodes : they 

 are frequently petaloid (e.g. Canna). In many acyclic flowers 

 (e.g. Nymphsea), the stamens and the petals are connected by 

 intermediate structures, of which it is difficult to say whether 



FIG. 278. Part of a staminal flower of 

 Ricinus communis cut through length- 

 ways : / / the basal portions of the 

 compoundly-branched stamens ; o the 

 anthers. (After Sachs.) 



