The Geography of Phytochemical Races

126 3 After the Ice
3.1 North America
3.1.1 Luetkea pectinata (Rosaceae)
Luetkea pectinata (Pursh) Kuntze, the sole member of the genus, is a small, trailing
species that grows in moist or shaded, primarily subalpine areas along the Pacifi c
Coast of North America ranging from Alaska to northern California, in the Cascades,
and in the Rocky Mountains from southern Alberta and British Columbia to eastern
Idaho and western Montana. Identifi cation of a rare tricetin derivative in a specimen
of L. pectinata from southern British Columbia (Wells and Bohm, 1988) prompted
wider sampling of the species throughout its entire range. The unusual compound,
identifi ed as tricetin 3′-O-glucoside [252] (see Fig. 3.1 for structures 252–255), was
subsequently seen in plants from all 27 sites visited (ranging from the Kenai Peninsula
in Alaska to Lassen National Forest in California). Quercetin 3-O-mono-
and diglycosides [253] were similarly ubiquitous, as was luteolin 7-O-glucoside
[254]. The fl avanone eriodictyol 7-O-glucoside [255] was observed in plants from
all but one of the sites. The only clear-cut difference that correlated with latitude
was the increased concentration of luteolin 7-O-glucoside in the four most southerly
populations studied (one from Washington, two from Oregon, and one from Lassen
National Forest, California). An acylated derivative of quercetin 3-O-glucoside (acyl
function not identifi ed) occurred sporadically in the northern part of the range, but
was consistently observed in specimens from southern British Columbia southward,
with increased amounts in the two most southerly locations, Crater Lake (Oregon)
and Lassen National Forest. An acylated derivative of luteolin 7-O-glucoside (acyl
function not identifi ed) was seen in scattered populations in the northern and central
parts of the species’ range but occurred as a major component in the two most
southerly sites. In contrast, the amount of eriodictyol 7-O-glucoside present in the
two most southerly sites was lower than seen in plants from any of the other sites.
It is diffi cult to assign any great signifi cance to these observations as they stand,
but the trends at the northern and southern extremes do suggest that a more detailed
analysis using one or more of the macromolecular techniques now available might
be worth the effort.
3.1.2 Tolmiea menziesii (Saxifragaceae)
Tolmiea menziesii (Hook.) Torrey and A. Gray, the sole member of the genus, occurs
from northwestern California through western Oregon, Washington, British Columbia,
and into Alaska. The taxon gained a measure of recognition through the work of
Doug Soltis and associates, which established it as one of the clearest examples of
autopolyploidy in nature (Soltis, 1984; Soltis et al., 1989). The distribution of plants
with different ploidy levels was also of interest in that northern populations, those
from Alaska, British Columbia, Washington, and northern Oregon, were tetraploid