328 University of California Publications in A(/ricuJfnr(il Sciences [Vol. 2 



between Eucrepis and Lagoseries (Barkhausia) ; parvifiora was given 

 similar intermediate status, but this is manifestly an error. In the 

 Flora Orientalis (Boissier, 1875) we find a statement which we trans- 

 late as follows: **As the achenes gradually diminish into a short beak, 

 it is doubtful whether this species belongs in Eucrepis or Barkhausia; 

 it affords a connecting link between the two sections." Boissier places 

 it under Barkhausia, presumably because the young flower heads 

 assume a nodding position. The unreliability of this character has 

 been pointed out. Moreover, recent taxonomists (e.g., Fiori, 1904) 

 have placed neglecta in Eucrepis, where it seems to belong rather than 

 in Barkhausia, as its fruits are variable in shape and even when they 

 are beaked the beak is very short, as shown in figure 5q. 



Section X, Youngia, is represented here by only one species, but 

 contains several others, of which one is fuscipappa (p. 331). These 

 comprise a very distinct group in certain morphological characters, 

 insomuch that some authors have suggested placing it in Lactuca. 

 But it is claimed (Bentham, and Hooker, 1873; Hooker, 1882) that the 

 species of this group (except two referred to Lactuca or Ixeris) 

 resemble Eucrepis more closely than Lactuca, and that japonica, which 

 is the type species of Cassini 's genus, Taungia, does not differ much in 

 floral characters from C. parviflora, a statement which is partially 

 true, although a number of differences do exist. It was noted above 

 that japonica (N^ 8) resembles hulhosa in having very short chromo- 

 somes. It is the only species known in the genus with 8 small chromo- 

 somes {japonica chromosomes total about 93 units in length as com- 

 pared with 137 for fuscipappa) and it was shown in Mann (1925) 

 that considering chromosome size alone it might have been derived 

 from tectorum (Eucrepis) by cross-division of all chromosomes. How- 

 ever, these two species are so widely different morphologically that 

 such a derivation seems hardly possible. On account of the strongly 

 flattened fruits in japonica (cf. fig. 6, v. v'), together with the other 

 differences noted in Hoffmann's key and the small size of the chromo- 

 somes, one may advocate the recognition of Cassini 's Youngia as a 

 genus intermediate between Crepis and Lactuca. Cassini (1831) in 

 the original diagnosis of Youngia states: "fruits oblong, more or less 

 flattened, . . . absolutely beakless" . . . [genus] "not to be con- 

 founded with Crepis because of the flattened fruits." Further com- 

 parative study of shape of fruits and size of chromosomes will be 

 necessary, however, before a final conclusion can be drawn. 



