CHARLES DARWIN'S FAVOURITE ORCHID - Catasetum species

Female Catasetum barbatum - image credit Dalton Holland Baptista





According to both the scientists at the Royal Botanic Gardens, Kew, and one of my personal heroes - David Attenborough, the orchid genus that Charles Darwin coveted above all other is Catasetum.

Unusual for plants within the orchid family, individuals are either male or female. The male produces a specific scent that attracts just once species of small, glossy, beautifully coloured bee.

Male Catasetum barbatum - image credit Maarten Sepp
The bee lands on the lip of the orchid and thrusts its head into the hood of the flower. In doing so the bee touches a trigger which stamps a bundle of pollen grains (known as pollinia) onto the bees back. This is held firmly in place by a viscous glue.

Understandably startled by its floral assault, rather than attempt to feed from second male Catasetum flower it chooses instead to search for nectar following a slightly different, but no less attractive scent. This would be the female Catasetum and to deceive the bee further the flower produced differs both in shape and colouration.

The bee places its head inside the female flower, and the pollinia fits perfectly inside a tiny aperture like a key in a lock. Pollination has been achieved.

The 'Sack-Shaped' Catasetum - Catasetum saccatum is a tropical South American species, and was actually discussed by Charles Darwin. His description of the plant included its ability to launches its sticky pollen sacs with explosive force, when an insect touches the hair-like trigger mechanism. He was ridiculed for reporting this by the naturalist Thomas Huxley. However, history has proven that Darwin's observations were both true and accurate.

For related articles click onto the following links:
CHARLES DARWIN'S FAVOURITE ORCHID - Catasetum species
CHARLES DARWIN'S GREATEST EXPERIMENT
CHARLES DARWIN'S LEGACY - 200 years on
DARWIN'S THEORY OF EVOLUTION
HOW TO GROW THE HYACINTH ORCHID - Bletilla striata
How to Grow Monkey face Orchids from Seed - A Warning!
HOW TO FEED ORCHIDS
HOW TO REPOT AN ORCHID
HOW TO WATER ORCHIDS
MONKEY FACE ORCHIDS
Naked Man Orchid - Orchis italica
SCHOMBURGKIA EXALTATA
THE ANGEL ORCHID
THE BEE ORCHIDS
The Angel orchid - Habenaria Grandifloriformis
THE BUTTERFLY ORCHID - Psychopsis papilio
THE FLYING DUCK ORCHID
THE MOTH ORCHID - Phalaenopsis species and cultivars
THE ORCHID MANTIS
The swaddled babies orchid - Anguloa uniflora 
THE VAMPIRE ORCHID - Catasetum macrocarpum
THE WHITE EGRET FLOWER - Habenaria radiata
THE WHITE EGRET FLOWER - Pecteilis radiata
WHAT IS AN ORCHID?
WHO WAS CHARLES DARWIN?

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