THALAMIFLOB^E. 219 



bifid, sometimes wanting, mostly separated by a short internocle 

 from the calyx. Stamens twice as many as the petals, or equal 

 to and opposite to the sepals, sometimes fewer, inserted with the 

 petals ; filaments awl-shaped, sometimes coherent; anthers innate. 

 Ovary sessile, or raised with the corolla and stamens on a short 

 stalk above the calyx, 1-celled, with a central placenta or with 

 2-5 dissepiments extending to the centre ; ovules few or nume- 

 rous ; stiymas 2-5, filiform, resembling the styles, but papillose 

 down the inner side. Fruit capsular, 1-celled, with a central 

 placenta, 2-5-valved, or splitting into 4-10 teeth above (fig. 354), 

 or 2-5-celled, loculicidally dehiscent, with the placentas adhering 

 to the septa ; seeds mostly indefinite ; the embryo mostly curved 

 round the perisperm (fig. 355), rarely straight or spiral, with 

 little perisperm ; radicle next the hilum. 



ILLUSTRATIVE GENERA. 



Tribe 1. ALSINE^E. Sepals distinct. 

 Sagina, L. 

 ALsine, Wahlenb. 

 Arenaria, L. 

 Stellaria, L. 

 Cerastium, L. 



Tribe 2. SILENRX. Sepals cohering 



into a tube. 



Dianthus, L. 

 Saponaria, L. 

 Silene, L. 

 Lychnis, L. 



Affinities, &c. The typical floral formula is S 5 P 5 A 5-f 5 G 5. The op- 

 posite entire leaves springing from thickened nodes, definite stamens, and 

 the character of the placenta and seeds serve to distinguish the great ma- 

 jority of tin's well-marked Order. The nearest relations of the Caryo- 

 phyllaceoa, as here defined, are unquestionably the Illecebraceae and Por- 

 tulacacese, which we separate more for the sake of convenience of distinc- 

 tion than on account of natural diversity, since in both those Orders there 

 is a variation between the hypogynous and perigynous conditions. The 

 Illecebraceae may be distinguished by their scarious stipules and utricular 

 fruit, and the Portulacacese by the 2-leaved calyx and by the stamens 

 when equal to the sepals being alternate, or opposite to the petals, since it 

 seems more convenient to keep the Mollugineee with Portulaeacese if they 

 are divided. The apetalous forms, and the alliance with the Orders just 

 named, connect this Order with the Amarantaceae and Chenopodiaceas 

 and several other families, all characterized by a curved embryo surround- 

 ing a floury perisperm. 



The placentation of the Caryophyllaceae is regarded by some authors as 

 forming one of the exceptions to the marginal type, the free central 

 column in mature ovaries being regarded as a product of the receptacle, 

 independent of the carpels. But the dissepiments exist in the early stages 

 of development, and are torn away during the expansion of the ovary : 

 hence there is no necessity to assume the independent origin of the pla- 

 centas. Monstrous blossoms of plants of this Order do not decide the 

 question, since these have been found with really independent growth of 

 the ovules from the base of the ovary, and with ovules developed upon the 

 margins of the carpels. Lychnis and some other genera have petals with 

 a scale-like outgrowth. Several species are dioecious. 



