Angraecum

Native: majority of the genus found in tropical Africa and Madagascar; one species found on Sri Lanka and three species in Japan and the Philippines; also found on the Comoros, the Seychelles, and the Mascarenes; having adapted to dry tropical woodland habitat bear quite fleshy leaves as a consequence
Type: most are epiphytes; a few are lithophytes
Size: flowers are large: 4 – 9 cm across; spur of the flower is 27–43 cm in length
Flowering: long-lasting flowers bloom from June to September in the wild with most flowers wilting by August; star-like waxy flowers are produced on 30 cm inflorescences arising from the stem; all have a long green spur at the back of the labellum
Colors: mostly white, but a few are yellow, green or ochre
Flowering stem: axillary; flower grows from the leaf axil
Growth pattern: monopodial; can grow to height of 1 m
Pseudobulb: do not produce pseudobulbs; instead the flowers grow from the leaf axils
Roots: tends to be few roots which attach to the bark of trees quite strongly; roots are dark gray, thick, and succulent; emerge from orchid's stem and can extend along the tree trunk for several meters
Known for: its especially long nectar spur; association with Charles Darwin who predicted its pollinator nearly 40 years before the moth was discovered; common name Darwin's Star Orchid; an intense spicy scent only at night
History:

First discovered by French botanist Louis-Marie Aubert du Petit-Thouars in 1798, but not described until 1822.

Charles Darwin who studied the relationship between orchids and their pollinators, deduced that there must be an insect with a mouth part long enough to reach the nectar in the tube. Otherwise the orchid could never be pollinated. At the time, he was not believed.

Nearly 40 years later, a large, night-flying moth was discovered to be this orchid's unique pollinator, proving Darwin's theory.

The story of the postulated pollinator has come to be seen as one of the most celebrated predictions of the theory of evolution.

   
Angraecum

These large waxy star-shaped orchids, known as the Darwin's Star Orchid, have the distinguishing feature of a very long spur. View the parts of the flower: