A monoecious plant has separate male flowers and female flowers occurring on the same plant. Plants that are dioecious (die-EE-shus) have either staminate or pistillate flowers on separate plants.
Shagbark Hickory (click here) is monoecious, producing separate male (staminate) and female (pistillate) flowers on the same tree. The male flowers are produced in drooping yellowish green catkins near the tips of twigs; these catkins are arranged in groups of 3 (catkins in each group sharing the same basal stalk) and they are 3-6" long. Individual male flowers are less than 1/8" (3 mm.) across, consisting of several stamens and an insignificant calyx; each male flower is partially hidden by a 3-lobed bract. The female flowers are produced in short greenish spikes (about 1/3" or 8 mm. long) at the tips of young shoots; there is typically 2-3 female flowers per spike. Individual female flowers are about 1/8" (3 mm.) long and ovoid in shape, consisting of a calyx and a pistil with spreading stigmata at its apex. The blooming period occurs from mid- to late spring as the leaves develop. The flowers are cross-pollinated by the wind. Fertile female flowers are replaced by nearly sessile clusters of 1-3 fruits that develop during the summer and mature during autumn of the same year.
