The marigold is an annual flowering plant with green leaves and orange, yellow, or red flowers. The marigold is often grown as an ornamental in flower gardens, as well as a border plant along the edges of vegetable gardens. The plants typically grow to a foot tall and have 2" flowers; they do well in full sun in dry rich soil and are low-maintenance plants. The marigold often has a pungent smell, though some later varieties have been bred to be scentless. It is said to deter common insect pests, as well as nematodes, and is hence often used in companion planting.
The petals are spicy and are sometimes added to dishes as a garnish.
References: http://www.itis.usda.gov/ (checked August 19 2002)
Marigolds is a short story by Eugenia W. Collier.