The Geography of Phytochemical Races

6.5 Lord Howe Island 273
Fig. 6.10 Compounds 556–559, amine derivatives from Sophora
(Salisb.) Taub., numbering ten or so (Polhill, 1991), to which the Juan Fernandez
Islands taxa belong, also occur on mainland South America, in Hawaii [the endemic
S. chrysophylla (Salisb.) Seem.], Lord Howe Islands, and New Zealand (Wagner
et al., 1990). There is also evidence to suggest that S. microphylla Ait., one of the
New Zealand species, also occurs on Gough Island in the southern Atlantic Ocean
(Markham and Godley, 1972). Sykes and Godley (1968) discussed transoceanic
dispersal of Sophora and other genera.
Our interest lies in a comparative study of the alkaloids of Sophora species
from the Juan Fernandez Islands, mainland South America, and New Zealand
(Hoeneisen et al., 1993). Five species were examined, S. masafuerana Skottsb.
and S. fernandeziana Skottsb. from the Juan Fernandez Islands, S. microphylla
Ait.and S. macrocarpa from mainland Chile, S. linearifolia Griseb. from Argentina,
and S. microphylla from New Zealand. Eleven alkaloids were isolated and
identifi ed as derivatives of matrine [556] (see Fig. 6.10 for structures 556–559),
sparteine [557], and anagyrine [558]. Ammodendrine [559] was also identifi ed.
The authors concluded that the alkaloids of the Juan Fernandez Islands species
were different from the other taxa and suggested that this indicated that the island
species had been isolated from the continental ones “for some time, thus allowing
for the evolution of different alkaloid patterns.” To my reading of these data, this
is an overstatement, there being only relatively minor structural differences among
the taxa compared. The information could just as well be used to argue for a close
relationship among all of the tested species.
6.5 Lord Howe Island
6.5.1 Carmichaelia (Fabaceae)
Lord Howe Island lies at 31°28′S, 159°09′E about 900 km east northeast of Sydney,
New South Wales, and 1500 km northwest of Auckland, New Zealand (Fig. 6.11.
The origin and evolution of this volcanic island have been described in detail by