Angraecum sesquipedale (Christmas star orchid)

Found in eastern and south-eastern Madagascar, from sea level to 100 m elevation.

Angraecum sesquipedale is an epiphytic orchid that can grow up to a metre high. It has two ranks of narrow, leathery leaves that are two-lobed at the tip and measure 22–30 cm long and 3 cm wide. The thick roots are greyish and produced on the lower part of the stem. The pale greenish flower stems emerge from between the upper leaves and have 2–6 flowers on stems that are shorter than the leaves. The creamy white flowers are large, fleshy and star-like. The sepals and petals are pointed and between 7–9 cm long. The lip is concave, 6.5–8 cm long, broad at the base, tapering to a long point and with a spur 30–35 cm long.

A hand-coloured lithograph of Angraecum sesquipedale by W.H. Fitch (1859) taken from Curtis’s Botanical Magazine (Image: RBG Kew).

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Angraecum sesquipedale (Image: RBG Kew)

In January 1862, Darwin wrote in a letter to Joseph Hooker, who had sent him some orchids: ‘I have just received such a Box full […] with the astounding Angraecum sesquipedalia [sic] with a nectary a foot long. Good Heavens what insect can suck it’. Later that year, Darwin predicted that the long flower spur must have co-evolved with a pollinator moth with an equally long proboscis. However, it was not until after his death, and 41 years after writing his letter to Hooker, that the pollinator was eventually discovered - the Malagasy subspecies of the African hawkmoth – which was given the scientific name Xanthopan morganii praedicta in honour of Darwin’s prediction. Although Darwin predicted ‘a moth’ as the pollinator, it was Alfred Russel Wallace who went one further and predicted the pollinator would be a hawkmoth. Some argue that the name praedicta actually refers to Wallace’s prediction rather than Darwin’s.

Angraecum sesquipedale is not the only species in the genus with a unique pollinator. Recently, a group of scientists, including one from Kew, discovered the first known instance of a cricket as a pollinator of a related species – Angraecum cadetti from Mauritius and Réunion.

All orchids are listed on Appendix I or II of the Convention on International Trade in Endangered Species (CITES), which makes it an offence to trade this species without a permit.

Christmas star orchid is cultivated as an ornamental.

The Millennium Seed Bank partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in Kew's seed bank vault at Wakehurst.

Number of seed collections stored in the Millennium Seed Bank: One.

The Christmas star orchid can be seen in the Princess of Wales Conservatory.

Alcohol-preserved specimens of Angraecum sesquipedale are held in Kew’s Herbarium, where they are available to researchers from around the world, by appointment. The details of some of these, including images, can be seen online in the Herbarium Catalogue.

Painting by John Day

John Day (1824-1888) was an English orchid grower who also painted hundreds of exquisite watercolours of the newly discovered orchids that were entrancing Victorian society. These watercolours were presented to Kew after his death and are now in the Kew archives. A selection of paintings, including one of Angraecum sesquipedale, was published in A Very Victorian Passion: The Orchid Paintings of John Day 1863-1888.

Search Kew's databases for more information on this species

Find out more about orchids

Orchid Research Newsletter

Swiss Orchid Foundation

Curtis’s Botanical Magazine (Wiley-Blackwell)

Kew Science Teams: Monocots III: Orchids

Orchid conservation at Kew

ARKive – Angraecum sesquipedale