SIMMONS, SARAH L.*, JOSE L. PANERO, AND MARK W. CHASE. Department of Botany, University of Texas, Austin, TX 78713. Jodrell Laboratory, Royal Botanical Gardens, Kew, Richmond, Surrey TW9 3DS, United Kingdom. - Molecular systematics of Staphyleaceae: a re-evaluation of its composition, ordinal placement, intra- and infrageneric relationships as inferred from rbcL and ITS sequence data.
The family Staphyleaceae is a small dicotyledonous family of trees and
shrubs traditionally thought to consist of five genera:
Staphylea, Euscaphis, Turpinia (subfamily
Staphyleoideae), Huertea, and Tapiscia (subfamily
Tapiscioideae), totaling 50-60 species. Distributed across both the
old and new world, the family is distinguished by having decussate,
pinnate, serrate, stipulate leaves, small pentamerous flowers
presented in paniculiform cymes, and fruits that are berries, inflated
capsules or follicles. The relationship of Staphyleaceae to other
families is controversial, and treatments have generally relegated the
family to either the Cunoniales or Sapindales. Recent analysis of
rbcL sequence data from representatives of each of the five
genera supports a novel placement of the core Staphyleaceae
(Staphylea, Turpinia and Euscaphis) within the
Geraniales. The data does not, however, support monophyly of the
family, suggesting a different ordinal placement for Huertea
and Tapiscia. Sequences from the internal transcribed spacer
region (ITS) of the 18S-26S nuclear ribosomal DNA were used to resolve
species relationships within the family. Parsimony analysis of the
ITS data set revealed relationships quite different form those
supported by morphology. This analysis suggests that traditional
generic groupings are polyphyletic and a re-evaluation of the
delimitation of the genera is necessary.
Key words: Euscaphis, ITS, rbcL, Staphylea, Staphyleaceae, Turpinia