220 ESSENTIAL ORGANS. THE STYLE. 



Boraginacese (fig. 403), where the four carpels, o, are sunk in the 

 torus, r, in such a way that the common style, s, formed by the union 

 of four basilar styles, seems to be actually a prolonga- 

 tion of the torus. When ovaries are thus attached 

 round a central prolongation of the torus, continuous 

 with a united columnar style, the arrangement is 

 called a gynobase (yvvvi, pistil, and /3<r/?, base). It is 

 well developed in Ochnaceae. In Geraniums there is 

 a carpophore or prolongation of the torus in the 

 form of a long beak, to which the styles are at- 

 tached. 



453. The form of the style is usually cylindrical, more or less filiform 

 and simple ; sometimes it is grooved on one side, at other times it is 



flat, thick, angular, compressed, and even petaloid, as in 

 Iris and Canna. In Goodeniaceae it ends in a cup-like ex- 

 pansion enclosing the stigma. It may be smooth and covered 

 with glands and hairs. These hairs occasionally aid in scat- 

 tering the pollen, and are called collecting hairs, as in Gold- 

 fussia or Ruellia. In Campanula they appear double and 

 retractile. In Aster and other Composite (fig. 404), there 

 are hairs produced on parts of the style, p c, prolonged 

 beyond the stigma, s; these hairs, while the part is being 

 developed, come into contact with the pollen and carry 

 it up along with them. In Vicia and Lobelia, the hairs 

 form often a tuft below the stigma. 



454. The styles of a syncarpous pistil may be either separate or 

 united ; when separate, they alternate with the septa. When united 

 completely, it is usual to call the style simple (fig. 399) ; when the 

 union is partial, then the style is said to be bifid, trifid, multifid, accord- 

 ing as it is two-cleft, three-cleft, many-cleft; or, to speak more correctly, 

 according to the mode and extent of the union of two, three, or many 

 styles. The style is said to be bipartite, tripartite, or multipartite, when 

 the union of two, three, or many styles only extends a short way above 

 the apex of the ovary. The style from a single carpel, or from each 

 carpel of a compound pistil, may also be divided. In fig. 314, 2, each 

 division of the tricarpellary ovary of Jatropha Curcas, has a bifurcate 

 or forked style, s, and in fig. 405, the ovary of Emblica officinalis has 

 three styles, each of which is divided twice in a bifurcate manner, ex- 

 hibiting thus a dichotomous division. 



455. The length of the style is determined by the relation which 



Fig. 403. Pistil of Erithricium Jacquemontianum, with one of the ovaries removed in front, 

 to show the manner in which the ovaries are inserted obliquely on a pyramidal torus, r, whence 

 the style appears to arise, ending in a stigma, s. 



Fig. 404. Summit of the style, t, of an Aster, separating into two branches, s, each terminated 

 by an inverted cone of collecting hairs, p c. The stigma, s, is seen below in the form of a band 

 or line on the inner curvature of the branches. 



