From the orthogonal contrasts, flowers of autogamous racemes produced more seedless pods than geitonogamous flowers (G = 5.1, P = 0.024), which in turn set more seedless pods than xenogamous racemes (G = 11.2, P = 0.001).
Distant xenogamous seeds were significantly less likely to germinate than seeds from geitonogamy, xenogamous and open visitation treatments.
Breeding biologies of papilionoid legumes are diverse, ranging from cleistogamous to obligately xenogamous (Kalin Arroyo, 1981).
recurvatum, fruit and seed set in autogamous and xenogamous hand pollinations were compared with that in open pollinated controls using ANOVAs.
An ANOVA on log transformed data showed this to be significantly less than in xenogamous hand pollinations (n = 97; Table 5).
Their analyses predicted that self-incompatible, xenogamous, polycarpic, non-nectiferous species of forested habitats should be pollen limited.
P/O ratio also indicates that the species is xenogamous, although geitonogamy and autogamy (only induced, not spontaneous) were also recorded.
The reproductive studies and the P/O ratio indicate that the species is xenogamous, as confirmed in field experiencies.
For example, (1) flower-visitation rates were quite different between the larger, faster pollinivores and the smaller, slower nectarivores; (2) all nectarivorous species moved almost exclusively between flowers of the same plant, whereas the low percentage of interplant flights made by several pollinivorous insects could be important to ensure some xenogamous
pollination; (3) most importantly, interspecific differences in per-visit pollination effectiveness were evident only in relation to the trophic habit: pollen-collecting pollinators deposited significantly more pollen grains per visit than did nectar-collecting pollinators.
Intermorph (i.e., legitimate: pin x thrum or thrum x pin) crosses and xenogamous
intramorph (i.e., illegitimate: pin x pin or thrum x thrum) crosses were made, and a similar number of flowers were left unpollinated as controls.