Leaf morphology
All individuals from the Bonin Islands were subjected to leaf phenotypic
analysis, except population SGi, which lacked collected sunlit leaves.
For each individual, 1–5 leaves were measured for the same 11 traits
outlined by Setsuko et al. (2023): total length, blade length, blade
width, hair density on the upper and lower surfaces of the leaf (i.e.,
number of hairs per 4 mm2), number of serrations per
30 mm, thickness of the leaf blade, leaf area, leaf mass per area, ratio
of blade length to total leaf length, and ratio of leaf blade width to
length. Principal component analysis (PCA) was performed on the measured
traits. The two individuals from the Mukojima Islands that exhibited an
admixed pattern were excluded from PCA (Figs. 1 and 2).
RESULTS