Biology Of Irises
Most species in the iris family are perennial herbs. These plants die back to the ground surface at the end of the growing season and then redevelop new shoots from underground rhizomes, bulbs, or corms at the beginning of the next growing season. A few species are shrubs.
The leaves of species in the iris family are typically long, narrow, and pointed at the tip with parallel veins and sheathing at the base of the plant or shoot. The flowers are erect on a shoot and are large, colorful, and showy, and they contain both female (pistillate) and male (staminate) organs. The floral parts are in threes: three petals, three sepals, three stamens, and a pistil composed of three fused units. The sepals are large and petal-like, and they enclose the petals which are erect and are fused into a tube-like structure in some species. The flowers may occur singly or in a few-flowered inflorescence, or cluster. The flowers produce nectar, are pleasantly scented, and are pollinated by flying insects or birds, although some species are wind-pollinated. The fruits make up a three-compartmented capsule containing numerous seeds. The leaves and the rhizomes of Iris species contain an irritating chemical which is poisonous if eaten.