Field-collected individuals of Jacquemontia curtissii (Convolvulaceae), a perennial herb, were cultivated in a greenhouse to control conditions for hand-pollinations and floral measurements. This work was companion to field studies on the effects of habitat fragmentation on pollination of this species, after attempts to determine compatibility were complicated by field conditions. Flowers last one day, open from dawn through mid-morning, and produce nectar as reward for pollinators. Each flower contains from .25 - 1 microliter of nectar, from 22-50% sugar on a wt/wt basis; larger nectar volumes usually correspond to lower sugar concentrations. Flowers on each individual were subjected to one of four treatments: not manipulated (autogamy), anthers removed (apomixis), selfed, or crossed. Five flowers on each plant received each treatment, except for crosses, where ten flowers were used, crossed with different individuals. Results show the species to be highly self-incompatible, and the lack of pollen tube growth in all treatments except compatible crosses demonstrates sporophytic self-incompatibility. Fruit set observed in the field can therefore be interpreted as evidence of pollinator activity, and successful transfer of pollen from another compatible individual.

Key words: breeding systems, Convolvulaceae, floral biology, flower, nectar, pollination