256 



ORGANOGRAPHY. 



The full understanding of the above terms is of great im- 

 portance in practical botany, and the arrangements of the 

 organs as thus indicated by them, have been used by DeCandolle 



and others as the basis of 

 Fig. 534. Fig. 535. some of their sub-divisions in 



their systems of classification. 

 Thus the term thalamijlorce 

 is applied to plants which 

 have polypetalous corollas, 

 and hypoyynous stamens un- 

 connected with the other 

 whorls, as in the Poppy {fig. 

 428) and Ranunculus {fig. 

 530). When the corolla is 

 polypetalous, and the sta- 

 mens are attached with it to 

 the calyx, as in the Cherry 

 {fig. 532), or upon the top 

 of the ovary, as in Campa- 

 nula, &c. {fig. 533), the term 

 calyciflortE is given. When 

 the corolla is monopetalous, 

 as in Primrose {fig. 531), the 

 term coroUifiorce is applied. 

 These terms will be more 

 particularly described here- 

 after when treating of Systematic Botany. 



It sometimes happens that the stamens not only adhere to the 

 ovary or lower part of the pistil, as in the epigynous form of 

 insertion, but the upper part of the stamens and pistil be- 

 come completely united also, and thus form a colunm in the 

 centre of the flower, as in the Orchis {fig. 534), and Birthwort 

 {Aristohchid) {fig, 535). The column is then termed the 

 gynostemium, and the flowers are said to be gynandrous. 



3. Union, — When the stamens are perfectly free and separate 

 from each other, as in the Vine {fig. 506), they are said to be 

 free or distinct; when united, as in the Mallow {fig. 537), they 

 are coherent or connate. 



This union may take place, either ])y their anthers, or l)y their 

 filaments. When the anthers cohere, the filaments being free, 

 the stamens are termed syngenesious or synantherous {fig, 536). 

 This union occurs in all the Compositie, in the Lobelia, Violet, 

 &c. When union occurs between the stamens liowevcr, it is 

 more connnon to see the filaments unite, and the anthers free. 

 The union by tlic filaments may take jtlace in one or more bun- 

 dles, the number l)eing indicated by a Greek numeral prefixed 

 to the Avord adelphmis, whicli signifies brotherhood. Tims, wlien 

 all the filaments unite together and form one bundle, as in the 



Fifj. 534. Flower of Orchis mascula. 

 The column in the centre is formed 

 by the union of the stamens and 



style Fig. .535. The pistil and 



stamens of Birthwort {Aristolochia). 

 The ovary is seen below, and the sta- 

 mens above united into a column 

 with the style. 



