ESSENTIAL FLORAL LEAVES. 95 



liypogynous, perigynous, and epigijnous are applied to stamens 

 (c/.p. 81). 



Cohesion. — Stamens may either be united together by their 

 stalks (filaments) or by their thickened heads (anthers). In the 

 former case they are termed mon-, di-, tri-, or polyadelphous, 

 forming respectively one, two, three, or more than three groups. 

 Monadelphous stamens are found in some papilionaceous flowers, 

 as gorse and broom. The lower parts of the ten filaments are here 

 united into a tube which surrounds the gynoecium. A somewhat 

 similar state of things exists in mallow and hollyhock. Many 

 papilionaceous flowers exemplify the diadelphous condition. Exa- 

 mination, for example, of clover, bird's-foot trefoil, pea, or bean 

 will show that the staminal tube is formed by the bases of 

 nine filaments only, while the remaining upper or posterior 

 stamen is free. The only British examples of more numerous 

 groups of stamens are the St. John's worts. The andrceciuni is 

 here commonly said to be triadelphous or polyadelphous, although, 

 as stated above, it is really an example of branching. 



The stamens are synantlierous or syngenesious when their anthers 

 cohere together into a cylinder. This is the case in the large group 

 of Composites, of which dandelion, daisy, thistle, sunflower, dahlia, 

 and groundsel are common examples. Pull off, for instance, one 

 of the disk florets from a single dahlia (double or quilled ones 

 have become abnormal by cultivation), and hold it up to the light. 

 Projecting from the mouth of the five-toothed tubular corolla is 

 a thickened fork. This is the upper part of the gynoeciuni. 

 Within the upper part of the translucent corolla is a dark rod- 

 like body, the united anthers, surrounding the middle of the 

 gynoeciuni, and below this are some wavy threads, the filaments 

 (cf. p. 126). By tearing open the corolla with needles these 

 points can be made out more clearly. The same thing can be 

 seen with greater difficulty in the much smaller florets of dande- 

 lion, &c. (fig. 44). In lobelia the stamens are both synantlierous 

 and monadelphous. Something similar takes place in the male 

 flowers of cucumber and vegetable marrow. 



Adhesion. — Stamens are sometimes united to the petals of a 

 polypetalous corolla, as is the case with the inner five stamens 

 of bladder-campion, and very frequently to the tube of a gamo- 

 petalous corolla, as in foxglove, dead nettle, primrose, speedwell, 

 and snapdragon. In either case they are termed epipetalous. 

 Split open a foxglove bell, and you will find the filaments of the 

 four stamens partly free and partly represented by prominent 

 ridges running down to the attachment of the corolla. 



Far more rarely there is adhesion between stamens and carpels. 

 The commonest examples of this are orchids, where the single 



