What is Angraecum?

The genus Angraecum, abbreviated angcm, is a genus of orchids that includes hundreds of orchid species. The Angraecum sesquipedale, also known as the comet orchid or angrek, is perhaps the most well known. These orchids are native to Madagascar. They are epiphytes, meaning that they often grow on host plants for support. The Angraecum sesquipedale is a large orchid that normally prefers high humidity, rich soil, and low altitudes in a tropical climate.

There are more than 220 species of orchid classified as Angraecum. They typically grow in Madagascar, tropical Africa, and southeast Asia. They can also be found growing in humid tropical regions, between sea level and 2,000 meters (6,561.7 feet). The Angraecum sesquipedale, or comet orchid, is just one of these. It's native to Madagascar and usually grows at altitudes below 100 meters (328.08 feet).

The comet orchid is a large orchid that typically requires heat and humidity to grow. It grows to about 12 inches (30 cm) tall and may produce up to six blooms. Its leaves are green, abundant, long, and narrow. The blooms are normally fragrant, large, waxy in appearance, and long-lasting. Flowers can be 7 to 14 inches (16.5 cm to 35 cm) in size and are generally white.

The Angraecum sesquipedale is an evergreen epiphyte that flowers through the winter. It won't usually thrive, however, unless the climate is warm, wet, and humid, offering rich soil and well-circulated air. In nature, it often grows in pools of decaying leaves and other vegetable matter, usually found among the branches of a host plant. In cultivation, the comet orchid generally needs to be watered and fertilized regularly.

Like other members of the genus Angraecum, the Angraecum sesquipedale's bloom has a spur at the rear of its lip. The bloom's nectar can be found at the bottom of this spur, which, in the Angraecum sesquipedale, is often up to 11.8 inches (30 cm) long. Charles Darwin's theories popularized the comet orchid when he suggested, upon observation, that there must necessarily exist a pollinator with a tongue or proboscis at least this long, otherwise the comet orchid could not exist.

Darwin's hypothetical pollinator was not discovered until years after his death. It's now known most commonly as the hawk moth, or Xanthopan morganii praedicta. The hawk moth may be the comet orchid's only pollinator. Hawk moths typically feed from the blooms at night, when the Angraecum sesquipedale releases its attractive fragrance.