Figure legends
Figure 1. Morphological diversity of species of Ruelliaused in this study. A. R. breedlovei . B. R. macrantha . C.R. elegans . D. R. lutea . E. R. matudae . F. R.
morongii . G. R. californica . H. R. hirsutoglandulosa . I.R. saccata . J. R. speciosa . K. R. longipedunculata .
Figure 2. Experimental design of crossing study, showing that
both allopatric and sympatric crosses were attempted within and across
major clades of Ruellia . Lines connect species pairs for which
crosses were attempted (all crosses attempted bidirectionally). Dashed
lines: allopatric species pairs. Solid lines: sympatric species pairs.
Circles next to species names colored according to flower color. Circles
are proportional to flower size (first axis of principal component
analysis in Supplementary Fig. 2) and depict an overall lack of
phylogenetic signal for flower color or size. Phylogeny rotated around
select nodes for visual clarity.
Figure 3. Left panel : F-statistic for analyses of variance that
compare interspecific distances for a given floral characteristic in
sympatric vs. allopatric species pairs. High values indicate that
sympatric species pairs diverge more for a given floristic
characteristic relative to allopatric species pairs. Low values indicate
equivalent divergences. Right panel : raw style length
measurements for each species pair for which a cross was attempted; each
pair represented by a vertical line and end points depict style lengths
for the two species. All sympatric species pairs differ by at least 21.8
mm in style length, while 23 of 28 allopatric species pairs differ by
less than 21.8 mm in style length.
Figure 4. Impacts of genetic distance, measured as
interspecific phylogenetic distance in a maximum likelihood phylogeny
(panels A & C) and flower shape, measured as euclidean distance in a
principal components decomposition of floral shape measurements (panels
B & D) on crossing success. Upper panels (A & B): allopatric
species pairs. Lower panels (C & D): sympatric species pairs.
Floral similarity and genetic distance significantly impacted crossing
success. Covariance in flower shape and geography evident in panel D (no
sympatric species pairs with a flower shape distance < 3). In
C & D, note that only one sympatric cross was successful. Points
staggered slightly on x-axis for visual clarity.