SYNGENESIA. 347 



essential in this Class being derived from the recep- 

 tacle, crown of the seed, and calyx. These Gartner 

 has illustrated with the greatest accuracy and skill, 

 but even these must not be blindly followed to the 

 destruction of natural genera. 



4. Polygamla necessaria. Florets of the disk fur- 

 nished with stamens only; those of the margin, or 

 radius, only with pistils ; so that both are necessary 

 to each other. This is well seen in the common 

 Garden Marigold, Calendula, in whose calyx, when 

 ripening seed, the naked and barren disk is conspi- 

 cuous. Othonna, Curt. Mag. t, 306, 768, Arctotis, 

 Osteospermum and Silphium, not rare in gardens, 

 are further examples of this Order, which I believe 

 is constant and founded in nature. We have no 

 British specimens either of it or the following. 

 Filago, at least as far as our Flora is concerned, 

 belongs to Gnaphalium. See Engl. Bot. t. 946, 

 1J93, &c. 



5. Polygamia segregata. Several flowers, either 

 simpleor compound, but with united tubular anthers, 

 and with a partial calyx, all included in one general 

 calyx. Of these the Globe-thistle, Echinops, and 

 Stoebe, with Seriphium and Corymbium, (which 

 two last require to be removed hither from the 

 abolished Linnaean Order Syngenesia Monogamia^) 

 have only one floret in each partial calyx ; Jungia 

 has three, Elephantopus four, others more. In 



