Plant Size and Pollinator Visitation in Cynoglossum Officinale

The number of bumblebee approaches to hound's tongue (Cynoglossum officinale) plants increased with increasing number of flowers per plant. The proportion of flowers visited after arrival of a bee decreased with increasing number of flowers. The net result of these two processes in shaded populations was that individual flowers on large plants received significantly more visits than those on small plants. This trend was repeated in open, unshaded populations but was not as pronounced. Plants in unshaded populations were approached more often than those in shade. In isolated plants, with no neighbours within 10 m, the number of approaches also increased with increasing number of flowers per plant. Compared with plants in populations, isolated plants received fewer approaches, but the proportion of flowers visited per approach was higher.