Geranium

A geranium is any of the 230 species of perennial, succulent, and shrub plants of the genus Pelargonium. Confusingly, the scientific name of the cranesbills is Geranium, and both genera are in the family Geraniaceae. (Linnaeus originally put both genera in one, and they were only separated in 1789 by Charles L’Héritier.)

Geraniums are extremely popular garden plants, and hundreds of cultivars have been developed from about 20 of the species.

Geranium leaves are usually alternate, and palmately lobed or pinnate, often on long stacks, and sometimes with light or dark patterns. The erect stems bear five-petaled flowers in umbel-like clusters called pseudoumbels. The shapes of the flowers have been bred to a variety ranging star-shaped to funnel-shaped, and colors include white, pink, red, orange-red, and fuchsia.

Horticultural geraniums fall into six major groups, with zonals subdivided further:

• Angel
• Ivy-leaved
• Regal or Martha Washington
• Shrubby-leaved
• Unique
• Zonal - erect and bushy
  • Cactus-flowered
  • Double-flowered
  • Fancy-leaved
  • Formosum hybrid
  • Rosebud
  • Single-flowered
  • Stellar

The first species known to be cultivated was Pelargonium triste, a native of South Africa. It was probably brought to the botanical garden in Leiden before 1600, on ships that stopped at the Cape of Good Hope, and in 1631 the English gardener John Tradescant bought seeds from Rene Morin in Paris and introduced the plant to England. The name Pelargonium was introduced by Johannes Burman in 1738.

Reference

• Maria Lis-Balchin, ed., Geranium and Pelargonium: History of Nomenclature, Usage and Cultivation (Taylor and Francis, 2002) ISBN: 0415284872