Cardtms and Cnicus tvhich appear to he dioecious. 21 



applicable. Linnaeus has indeed use the term Flos andyogi/nns, 

 but it is not, I believe, known what precise meaning he intend- 

 ed to convey by it ; from which cause it has fallen into disuse. 



It being "a matter of some interest to ascertain what propor- 

 tion of the species of the genera I have mentioned, or of those 

 allied to them, have the male and female flowers on different 

 plants ; and as this can only be effected by examining nume- 

 rous specimens in their wild state, it may be useful to point out 

 some of the most obvious and striking distinctions between the 

 female and antheriferous capitula, and which are such as may 

 be readily observed in a cursory survey of the plants : to de- 

 termine whether the flowers are male or hermaphrodite, re- 

 course must be had to the seeds. 



The flowers of the antheriferous capitulum are much larger, 

 and the laciniae more divaricate, the perfect antherje rise be- 

 yond the lacinias and embrace the style ; in the female the 

 abortive antherae scarcely appear beyond the tube of the co- 

 rolla, and, being generally very small, are not seen except 

 upon a close examination : this gives the female capitulum a 

 uniform colour and appearance, which is destroyed in the an- 

 theriferous one by the projecting of the antherae, frequently of 

 a different shade of colour from the corolla, and which, even 

 when withered, remain exserted nearly to the tips of the la- 

 cinifE, producing a ragged and discoloured appearance. 



The stigma of the female is almost always nmch more de- 

 veloped, and in general somewhat waved ; it is very remark- 

 ably so in the female Serratula tinctoria. 



In Cnicus arvensis there is another circumstance which di- 

 stinguishes the sexes even after flowering, and which is per- 

 haps more striking than any other ; this is produced by the 

 pappus. In the female, the pappus at the time of flowering 

 is shorter than the tube of the corolla, and nearly as long as 

 the scales of the involucrum; after flowering it lengthens very 

 considerably, and, when the seed is ripe, is twice its former 

 length, and entirely conceals the persistent corolla : when the 

 seeds are to be dispersed, the female plants are white with the 

 large and abundant papjms, which appears jirojecting beyond 

 the scales of the hivolucrum before it is discharged by their 

 expansion. 



In the male, the pappus at tlie time of flowering is nearly of 

 the same length as in the female : it however never increases 

 afterwards, and is concealed after flowering by the withered 

 corolla and antherae : at this period, therefore, the male ])lants 

 are distinguished by the brown withered capitula, which ap- 

 pear generally to perish without discharging their abortive 

 seeds and useless pappus. 



My 



