Revision of Passiflora Subgenus Decaloba ... - Passion Flowers

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is primarily an indicator of flower size. Because PC1 and PC2 are by definition
not correlated, this division of floral and vegetative characters between these first
two PCs indicates that there is little correlation between floral and vegetative
characters among the entities in the P. suberosa complex.
A PCA analysis of the data set for the P. suberosa complex based on 31 floral
characters (Tab. 5.1) is presented in Fig. 5.2. Principal components I, II, and III
account for 47.1%, 15.0%, and 9.5% of the variation, respectively, for a total of
71.6%. Principal component axis I is most highly influenced by (presented in
decreasing order of component loadings) (Tab. 5.3): (1) androgynophore length,
(2) sepal length, and (3) length of the filaments in the outer coronal row; axis II by
(1) number of filaments in the inner coronal row, (2) pedicel length, and (3)
number of filaments in the outer coronal row; axis III by (1) pedicel length, (2)
stipe length, and (3) nectary width. The PCA plots of axes I and II and axes I and
III clearly separate P. tridactylites, P. suberosa ssp. suberosa, P. suberosa ssp.
litoralis, and P. pallida. The first and third principal components are a measure of
overall flower size and PC2 is mostly a measure of the relationship among the
number of filaments present in each coronal row. When PC1 and PC3 of floral
characters are plotted for individual plants (Fig. 5.2), individuals from the same
species and subspecies tend to cluster together although there is limited overlap
among entities of P. suberosa ssp. litoralis and P. pallida, possibly resulting from
hybridization. The pattern reflected in the scatter plot of the first and third
components in Fig. 5.2 strongly relates to the overall size of the flower, with