500 



just below the limb, which causes their florets to project, 

 in a more elongated manner, than in the discoidei, or other 

 compound flowers." 



" Section 3rd. Discoidei. The first subdivision of 

 these, polt/gami aqualis," (consisting of such as have all 

 the florets furnished with stamens and pistils, and all pro- 

 ducing seed,) "are distributed according to the receptacle, 

 whether naked, chaffy or hairy, and their seed-down, like 

 the semijiosculosi." 



"The second subdivision, polygamic/, superflua, have 

 female florets in the circumference, but these are tubular, 

 not ligulate or radiant. So that the flowers, though they 

 have a marginal series of female florets, cannot be called 

 radiated." We have here extracted the ideas of Linnaeus 

 from his remarks on Artemisia, which seem to refer to 

 the whole of this subdivision, and are certainly correct, 

 though they interfere with the distribution of the order 

 before us in the Genera Plantarum, and seem to have 

 been unintelligible to the editor of the Prcelectiones ; — see 

 his note in p. 539 of that work. 



"Section 4th. Radiati." (Marginal florets radiant.) 

 " The first subdivision is polygamia superflua," (all whose 

 florets are capable of producing perfect seed, though the 

 marginal radiant ones have no stamens.) 



These are distinguished by the presence or absence of 

 seed-down, or of a membranous border to the seed, and 

 by the nature of their receptacle, whether naked or 

 chaffy. 



The second, polygamia frustranea, have imperfect or 

 defective female or neuter florets in the circumference, 

 producing no seed. These in Centaurea are tubular, and 

 neuter ; in the rest ligulate, furnished with rudiments, 

 more or less evident, of a pistil. 



The third, polygamia necessaria, have effective seed ; 

 bearing female florets in the circumference only. 



" Section 5th. Monogamia." (Such as have but one 

 floret in each partial calyx.) 



