Am. Kiers et al., Morphologically defined Cichorium (Asteraceae) species reflect lineages based on chloroplast and nuclear (ITS) DNA data, SYST BOT, 24(4), 1999, pp. 645-659
Cichorium spinosum and C. bottae are morphologically well diagnosed species
. The remaining four species in the genus, C. intybus, C. endivia, C. pumil
um, and C. calvum, are usually difficult to distinguish because they differ
primarily in quantitative characters. However, our study indicates, that t
hese species are not intermixed in a multivariate analysis of morphological
characters. A cladistic analysis of restriction fragment length polymorphi
sms and trnL-trnF sequences of the chloroplast genome and nuclear ribosomal
DNA sequence data obtained from the six Cichorium species and nine possibl
e outgroup genera indicates that 1) Cichorium has an isolated position with
in the tribe Lactuceae, 2) C. bottae is sister to all other species of Cich
orium, and 3) the remaining species are divided into two main clades, one c
onsisting of C. calvum, C. pumilum, and C. endivia and the other consisting
of C. intybus and C. spinosum.