BREEDING SYSTEM,POLLINATION, AND POLLINATOR LIMITATION IN A PERENNIAL HERB,AMIANTHIUM MUSCAETOXICUM (LILIACEAE)

Observations of insects on Amianthium muscaetoxicum suggested that at least 16 species can serve as pollinators, although the chief pollinators appear to be beetles. Five species from three coleopteran families appear to be the most important pollinators. Experimental manipulations suggest that Amianthium is nearly self-incompatible and that fecundity and fruit set levels are at least partly pollinator limited. Outcrossed plants have higher fruit set and fertility levels than unmanipulated plants, and unmanipulated plants display higher levels than self-pollinated plants. Self-pollinated plants produce a few very small seeds, of which only a small percentage are viable. Fruit set levels in unmanipulated plants in one population were consistent over a 2-yr period.