Assertion: mechanical barrier | /r/RelatedTo | flower
Facets:
Source sentences:
text: Furthermore, if mating is attempted, then it may be preferable, even for males , to avoid wasting gametes , an issue that is particularly relevant for plants in terms of wasting pollen , and particularly so if that pollen is insect transferred (thus the utility of mechanical barriers associated with flowers that can bar all but a preferred pollinator ).