Am. J. Bot. Join BSA Today!
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gottlieb, L. D.
Right arrow Articles by Ford, V. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gottlieb, L. D.
Right arrow Articles by Ford, V. S.
Agricola
Right arrow Articles by Gottlieb, L. D.
Right arrow Articles by Ford, V. S.
(American Journal of Botany. 1999;86:428-435.)
© 1999 Botanical Society of America, Inc.

The status of Clarkia australis (Onagraceae)1

L. D. Gottlieb2 and V. S. Ford

Section of Evolution and Ecology, Division of Biological Sciences, University of California, Davis, California 95616

Clarkia australis and C. virgata grow on the western slope of the central Sierra Nevada of California. Clarkia australis was established to accommodate populations of C. virgata from south of the Tuolumne River that could not be successfully hybridized to populations north of the river. Although the species is maintained in the new Jepson Manual, its validity has been questioned because only two populations were originally tested, and they had no useful morphological traits that distinguished them from C. virgata. We report here the results of a large program of interpopulation hybridizations that show that C. australis is distinct and that its reproductive isolation from C. virgata is complete and absolute and reflects a compatibility block that apparently causes abortion of hybrid seeds in early development. Both species include populations north and south of the Tuolumne River and, in general, those of C. australis occupy higher elevations. Morphologically, the species are extremely similar though the mean values of several dimensions of the petals are different. However, significant variation among their populations has the consequence that, at present, the only certain way to assign particular populations to species is to test their compatibility with previously tested populations.

Key Words: Clarkia australis • Clarkia virgata • hybrid incompatibility • Onagraceae • reproductive isolation • speciation






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1999 by the Botanical Society of America, Inc.