Volume 12, Issue 3 (1989)This issue of Volume 12 was published 9th January, 1990.
Wood and Bark Anatomy of the New World Species of Ephedra
Morphological Stasis abd Molecular Divergence in the Intercontinental Disjunct Genus Datisca (Datiscaceae)
Aaron Liston, Loren H. Rieseberg, and Thomas S. Elias
Steps Toward the Natural System of the Dicotyledons
William C. Dickison