DIPSACALES. 



557 





and shrink up more or less completely. (Compare Fig. 593 ^, 

 B}. Style 1, stigma tripartite. Endosperm absent; embryo 

 straight, with the radicle directed upwards. 



The inflorescences are dichasia, or uniparecl scorpioid cymes with the 

 branches developed in the axil of the second bracteole, Both the bracteoles are 

 generally present and frequently form 4 very regular, longitudinal rows on 

 the branches of the inflorescence. 5 stamens do not occur (except perhaps in 

 Patrinia). The suppression of stamens and carpels takes place most readily 

 on the anterior side of the flower and that turned towards the first bracteole 

 (a) (Fig. 593), whose branch is suppressed in the dichasiutn ; after this the pos- 

 terior median stamen is next suppressed. 



By the vegetative characters as well as 

 by the inflorescence and the flower, the 

 order is allied to the Caprifoliacese and 

 especially to the Sambucese. 



In the least modified (oldest) 

 forms, Patrinia and Nardostacht/s, 

 there is an almost regular flower, 

 a 5-merous calyx, 4 stamens, and 

 3 loculi in the ovary, 2 of which 

 however are barren. The stamens 

 in ValerianeUa are reduced to 3, in 

 Fedia to 2 (posterior), and the 

 calyx is less distinctly 5-dentate ; 

 the 2 empty loculi in the ovary 

 are still visible. Fedia has a small 

 spur at the base of the corolla. 

 Valeriana has a very reduced, hair- 

 like calyx (pappus), an unsymmet- 

 rical, salver-shaped corolla with a 

 sac-like, nectariferous spur at the 

 base, 3 stamens and only 1 loculus 

 in the ovary (Figs. 594, 593). Cent rantlms (Fig. 593) is still 

 further reduced. The corolla has a spur and only 1 stamen ; 

 unipared scorpioid cymes with 4 rows of bracteoles. In the last two genera 

 there is a peculiar wall in the corolla-tube, which divides it longitudinally 

 into two compartments (indicated by a dotted line in Fig. 593), one of which 

 encloses the style. This wall is low in Valeriana, but in Centranthus it reaches 

 as far as the throat. The rays of the pappus are pinuately branched and 

 rolled up before the ripening of the fruit. 12-20 in number (Fig. 594 A, B). 



Viil. ptficinalis and others are protandrons : in the first period the stamens 

 project from the centre of the flower (Fig. 595 a), the stigmas in the second 

 (li) when the stamens have become bent backwards. (I', dioica is dioecious 



FIG. 593. A Diagram of Valeriana 

 officinalis. B Diagram of Centranthus. 



