40 E. B. Babcoc\ 



is intermediate and occurs in the southern half of Italy, and 

 chondrilloides is most recent and is found only in a limited area 

 extending from Trieste into southern Austria and northern Dal- 

 matia. (Associated with the foregoing are the two polyploid 

 species, C. incana and C. taygetica, of southern Greece.) In the 

 argolica-multiflora group, however, the relation between distri- 

 bution and the morphological evidence of relative age is re- 

 versed. Both argolica and tubaeformis are the least specialized, 

 particularly in achenial features, and each is known only from a 

 single small area in Greece, whereas dioscoridis is abundant in 

 parts of southern Greece, and multi flora, the most reduced 

 species, occurs on the islands and shores of the Aegean Sea in 

 eastern Greece and western Asia Minor. Hence these two groups 

 of species illustrate very well the difficulty which was recognized 

 by Willis"" in applying the "age and area" hypothesis to very 

 small groups of species — the pannonica group is in agreement 

 with the hypothesis, but the argolica group is not. This, how- 

 ever, is merely an incidental observation. The main point is that 

 both groups form part of the Eucrepis assemblage and occur in 

 the same distributional area. 



Definitely associated with the foregoing species, although not 

 closely related to any of them nor to each other, are two remark- 

 able species, C. patula, an endemic of northern Algeria, and C. 

 tenuifolia, which is distributed from the western Himalayas to 

 Mongolia. The former is apparendy a relic which combines a 

 number of primitive features with extreme reduction of the 

 pappus, a combination of characters that is unique in the genus. 

 The latter is believed to have originated as an interspecific 

 hybrid between two 8-chromosome species followed by amphi- 

 diploidy and subsequent alterations in chromosome number.* 



Turning now to other Eucrepis species with derived chromo- 



