Great Basin Naturalist


The effect of complete defoliation, prior to flower stalk appearance, on the reproductive success of foothill deathcamas, a toxic range plant, was studied in northern Utah. Defoliated plants did not replace their leaves. Defoliation had no effect on total number of flower stalks produced but did significantly slow the rate of stalk emergence and reduce the number of plants that produced open flowers. The number of leaves produced by control plants was also positively associated with the probability of producing a flowering stalk. Few plants in either defoliated or control treatments set seed, probably because of inactivity of pollinators during a cold and wet spring. It is suggested that species, such as deathcamas, which either produce leaves early in spring or are liliaceous geophytes, may be especially vulnerable to herbivory.