ants eis cas la cea ala lag ash IS 
MODERN SYSTEMATIC TREATMENT OF ASTER 
RECOGNITION OF SEGREGATE GENERA 
During the Linnaean period of Aster history, the steady en- 
largement of knowledge had changed the total of 30 species pub- 
lished by Linnaeus in 1753 to 107 listed by Nees in 1818. The 
American representatives had increased not only numerically but 
proportionally, from Linnaeus’ 20 to Nees’ 82, the latter number 
being substantially anticipated by Muhlenberg, who catalogued 81 
American species in 1809. 
With the year 1818, Nees’ Synopsis and its 107 species marked 
the culmination of the Linnaean period of the one cohesive genus ; 
and the publication by Cassini of his Ewryza * in the same year, 
1818, marked the distinct entrance upon an epoch of disintegration, 
which we have already called the period of Segregation, because 
marked by the recognition of segregates from Aster as distinct 
genera. Cassini had already published well-founded segregations 
like Agathaea, 1815, Galatella, 1817; but in 1818 his separation 
of Eurybia was the beginning of a series of temporary cleavages of 
certain Asters from the genus, segregations which have been 
repeatedly united and separated since, a characteristic of this 
modern period. - 
Cassini's segregate genera, 1815—1829, established or recog- 
nized by him, were the well-known Eurybia, Galatella, Calliste- 
phus, Calimeris, Felicia, Agathaea, Munychia; also Printzia, 
Zyrphelis, Chiliotrichum, Polyarrhena, Henricia, Brachycome, 
Charieis, and Paquerina. 
Lessing in his Synopsis generum Compositarum, 1832, estab- 
lished several additional segregate genera, Gymnostephium, Lepto- 
coma, and Rhinactina. 
Nees’ Genera et Species Asterearum, 1832, followed immedi- 
ately, and made a larger number of segregates than any author 
before or since. He accepted Cassini's genera and Lessing's; he 
*Cassini in Dict. des Sciences naturelles, 16. 1818. 
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