The Geography of Phytochemical Races

206 4 Intercontinental Disjunctions
One of the noteworthy observations arising from these studies is the scarcity
of fl avones in the genus, and the possibility that their presence may represent the
primitive condition (Averett et al., 1986). Thus, it is of interest that sect. Skinnera is
characterized by the uniform presence of the fl avones apigenin and luteolin, at least
according to the Averett et al. study. The three New Zealand species are further distinguished
by the presence of sulfate derivatives of the fl avones, such as 7-O-sulfates
according to Averett et al. (1986) and 7-O-glucuronidesulfates according to Williams
and Garnock-Jones (1986). The fourth member of sect. Skinnera, F. cyrtandroides,
has only one fl avone, apigenin 7-O-glucoside according to Averett et al. (1986), as
well as an array of fl avonol glycosides in line with the other members of the section.
Averett et al. (1986) also pointed out that the simplifi ed fl avonoid profi le of
F. cyrtandroides is in accord with the idea that it is the most recently derived species
in the section (Raven, 1979). This would also fi t with the comparatively young age
of Tahiti, estimated to be about 2 million years by means of potassium-argon dating
(Dymond, 1975). Also, the small fl eshy fruits of F. cyrtandroides, the westerly wind
currents, and the similar distribution patterns of other species would argue in favor
of long-distance dispersal from New Zealand.
A cladistic analysis of morphological and chemical features revealed the relationships
pictured in Fig. 4.14-A (Williams and Garnock-Jones, 1986), wherein
the Tahitian species, F. cyrtandroides, is sister to the clade comprising the three
New Zealand species. This defi nes the New Zealand clade as monophyletic based
upon gynodioecy and the presence of sulfates. This arrangement suggests that
the Tahitian and New Zealand species shared a common ancestor, which, presumably,
no longer exists. Crisci and Berry (1990) reexamined this system using
additional morphological characters as well as fl avonoid data. However, they
Fig. 4.14 Cladograms from Pacifi c Island Fuchsia study