Gladiolus is a genus with 276 species of flowering plants in the family Iridaceae, occurring in Mediterranean Europe, tropical Africa, South Africa and Asia. The plural for it is gladioli or gladioluses. The genus name is derived from Latin gladius meaning a sword, in referring to the sword-shaped leaves. The genus is sometimes known as Sword Lily.
Gladioli are half-hardy plants in temperate climate. The plants grow from rounded, symmetrical corms that are enveloped in several layers of brownish, fibrous tunics. The stems are usually unbranched, producing 1-9 narrow, sword-shaped, longitudinal grooved leaves, enclosed in a sheath. The lowest leaf is reduced to a cataphyll. The leaf blade is either plane or cruciform in cross section.
The large flower spikes are one-sided, with secund, bisexual flowers. Each flower is subtended by 2 leathery, green bracts. the flowers are ranged from pink to reddish or light purple with white, contrasting markings, or white to cream or orange to red. The almost identical sepals and petals (collectively known as tepal) are united at their base into a tube shaped structure. The dorsal tepal is the largest, arching over three stamens. The outer three tepals are narrower. The funnel-shaped perianth has the stamens attached to its base. The style has three filiform, spoon-shaped branches, each expanding towards the apex.
The attractive flower spikes of the Gladiolus makes it a popular flower for the cut-flower industry. It is extensively hybridized and now come in many varieties.
Originally, South African species were pollinated by long-tongued anthrophorine bees. However changes in the pollination pattern now see pollination by sunbirds, noctuid and sphingid moths, long-tongued flies and several others. Gladioli are used as food plants by the larvae of some Lepidoptera species including the Large Yellow Underwing.
Gladioli grow well in full sun, moist, well-drained soil. Propagation is by corms lifted in autumn, stored over winter, replanted in spring. Pests and diseases are aphids, slugs, snails, grey mould, and root rot.