Ornamental Bulbous Plants

Spring-Flowering

• The average person quickly understands an example of an ornamental bulbous plant when you mention spring-flowering bulbs such as tulips (Tulipa), amaryllis (Hippeastrum), reticulate irises (Iris reticulata) and daffodils (Narcissus), all true bulbs. Corms that produce notable springtime blooms include crocuses (Crocus) and snowdrops (Galanthus). Examples of tubers are winter aconites (Eranthis), Italian arum (Arum italicum) and the knobby-looking tubers of windflowers (Anemone blanda). Among the most widely recognized spring-flowering rhizome plants are bearded irises and lilies-of-the-valley (Convallaria), according to the American Horticultural Society's "A-Z Encyclopedia of Garden Plants."

Summer-Flowering

• In the warm of summer, other bulbous plants display attractive flowers. Montbretias (Crocosmia), crinums (Crinum), lilies (Lilium) and surprise lilies (Lycoris) grow from scaled or smooth-skinned bulbs. Lilies-of-the-Nile (Agapanthus) grow from fleshy rhizomes and dahlias (Dahlia) from plump, firm tubers, while foxtail lilies (Eremurus) grow from a spider-like spray of many thin tubers. Gladiolas (Gladiolus) produce tall flower spikes from large corms.

Autumn-Flowering

• Many people overlook the ornamental bulbous plants that flower in the short, cool days of fall. Fall-blooming crocuses (Crocus and Colchicum) are officially corms, and cyclamens (Cyclamen) grow from small tubers. Black calla (Arum pictum) produces its blackish-purple flower from a tuber.