Arizona-Sonora Desert Museum Digital Library

The cucurbits, as they are called, number 750 species worldwide; most species are vines. The flowers vary from barely noticeable to large and conspicuous. The fruits range from small and dry to large and tasty; the latter include cucumbers, squash, and melons. Gourds are hard-shelled squash that are used after they dry.

Two genera of bees (Peponapis and Xenoglossa) are tightly associated with this plant family. Squash or gourd bees are more effective pollinators of cucurbits than most other bees. They seem to be holding their own under competition from introduced honeybees (which collect the pollen but are inefficient pollinators of these flowers), probably because squash bees are active earlier in the morning.