MOTLEY, TIMOTHY J.*, LENA STRUWE, AND VICTOR A. ALBERT. The New York Botanical Garden, Bronx, NY 10458-5126. - Molecular Systematics of Hawaiian Hedyotis (Rubiaceae).
Hedyotis is a large tropical to subtropical genus of more than
250 species. The genus is represented by 22 species in Hawai`i.
Twenty species are endemic and two are naturalized weeds. Formerly
Hawaiian Hedyotis was treated as two genera based primarily on
fruit characteristics (drupes or capsules). Presently, the Hawaiian
species are placed into two subgenera, Polynesiotis and
Kadua, based on inflorescence rather than fruit characters. The
drupaceous species now make up two of the six sections within the
subgenus Polynesiotis and Kadua is represented by a
single section. Cladistic analysis of nucleotide sequence data from
the nuclear ITS regions 1 and 2 indicate that: (1) the section of the
subgenus Kadua is nested within the sections of the subgenus
Polynesiotis; (2) the drupaceous taxa and the capsular taxa
form two distinct clades that are further resolved into clades which
for the most part delimit the taxonomic the sections and; (3) within
the capsular-fruited clade section Bikkiocarpa (one species
endemic to east Maui) is placed within the section Gouldiopsis
and varies morphologically from other members of this section by
having rounded flower buds and elongate capsules. This research is
supported by the Lewis B. and Dorothy Cullman Foundation.
Key words: Hawai`i, Hedyotis, ITS