ABCDEFGHIJKLMNOPQRSTUVWXYZ

Species distribution and density. Darker squares represent higher density of members of this family.

Introduction

Orchid family

A family with highly specialised flowers, adapted for insect pollination. Fruits contain thousands of seeds that are so small that they appear dust-like when dispersed by the wind. The family is cosmopolitan and has many uses apart from their attractive, colourful flowers used in the flower industry.

Distribution

Cosmopolitan, distributed from the tropics to the subarctic zone. Infrequently found in dry areas or high altitudes. Southern Africa has high levels of diversity in the Western Cape and along the Drakensberg escarpment.

Number of genera in the world

ca. 800

Number of species in the world

ca. 20 000

Number of genera in the Flora of southern Africa region

53

top

Number of species in the Flora of southern Africa region

529

Well-known southern African genera

Bonatea, Brownleea, Corycium, Disa, Eulophia, Habenaria, Holothrix, Mystacidium, Polystachya, Satyrium

Growth forms

Terrestrial, epilithic or epiphytic, very rarely a climber (e.g. Vanilla). Mostly deciduous perennial herbs, with rhizomes, corms, tuberous roots or pseudobulbs.

Habitats

Bushveld, savanna, karroid and thorn scrub, fynbos and grassland; often associated with wetlands.

Flagship species

Disa uniflora (red disa; rooidisa [A]) grows along stream banks and in moist places and makes a spectacular display when in full bloom during the summer months. This species is one of the best known South African orchids and the floral emblem of the Western Cape. The red disa has been grown in England at least since 1891 and is the parent to many hybrids cultivated by orchid growers. The flowers are usually red but can vary from pink to yellow and even white. It is also cultivated in New Zealand as a cut flower. (Photo: RO).

top

Significance of the family

The main economic importance of the family is in the flower industry as ornamentals and long-lasting cut flowers. The Mexican species *Vanilla planiflora has long been cultivated for the aromatic flavour of its pods (beans). The tubers of some African species (e.g. Satyrium) are harvested as a food source. A large number of species are used in traditional medicines. Various parts of orchids are used in traditional folklore in Africa as love, death and fertility charms, to ward off evil or as protection from lightning. Some species are also used as aphrodisiacs. (Photo: RDV).

Diagnostic characters

Herbs usually with rhizomes, pseudobulbs  or tubers . Leaves alternate, usually basal, spirally arranged or in 2 rows  with parallel veins. Flowers irregular with complex structure . Androecium and gynoecium fused into a gynandrium . Calyx consists of 3 sepals, green or coloured. Corolla consists of 3 petals, lower one modified into a lip . Stamens not visible and highly modified and fused with style to form a column. Pollen aggregated into a waxy clump to form pollinia, sometimes covered by anther caps . Ovary inferior , 1-locular with 3 carpels. Fruit a capsule  with numerous minute seeds.

Did you know?

The Orchidaceae is one of the largest flowering plant families and, in addition to the natural species, more than 70 000 cultivars and hybrids have been cultivated from this family.