Orchid Evolution and the Black Orchids of Belize

They may be the oldest family of flowering plants in the world, and are certainly one of the largest: between 21,950 and 26,044 species share the name Orchidaceae.

Hammer orchid:By Brundrm (Own work) [CC-BY-SA-3.0), via Wikimedia Commons

A favorite of cultivators around the globe, orchids may just be on the most remarkable examples of plant diversity. From the Australian Hammer orchid’s (above) near perfect mimicry of a female wasp (complete with sexual pheromones) to the Madagascar orchid’s elongated nectar tube that can only be pollinated by a single species of moth (below), orchids are renown not only for their beauty but also the individuality expressed between different species.

Madagascar (or Darwin’s) orchid; By Johan Spaedtke (Own work) [CC0], via Wikimedia Commons

But what caused these eye-catching flowers to become so unique? The secret lies millions of years ago, during the age of the dinosaurs.

100 million years ago, orchids existed as one of the earliest families of flowering plants. To ensure genetic diversity, orchids relied on insects such as bees and wasps to pollinate between plants. But there was a hitch: insects had already evolved to be attracted to nectar 12 million years earlier, a reward the orchids simply did not possess.

So natural selection took control, along with a species characteristic of flowering plants: genetic redundancy, which allows both mutated and original genes to coexist, and be expressed, simultaneously. These two evolutionary factors are the main force behind orchid evolution. Together they allowed for the ability of the orchid’s labellum, or lip, to evolve independently from the rest of the plant. Over millions of years, each species of orchid adapted independently, and often specialized to attract a certain species of insect. From mimicry to eye-catching colors to lips that house protective colonies of ants, each orchid developed on its own path, resulting in the thousands of unique species present today.

Black orchid of Belize; used by permission from 5Blue Media

In Belize, the black orchid (Prosthechea cochleata), also known as the cockleshell or clamshell orchid, exemplifies both the beauty and strangeness of the Orchidaceae family. Actually a deep purple hue, Belize’s national flower features an “upside-down” lip, causing the black orchid to appear to some like a 5-legged octopus.

As opposed to most orchid’s limited flowering season, black orchids bloom year-round as an “epiphytic” flower that shuns the earth populated by other “terrestrial” orchids in favor of Belize’s endemic trees. While common throughout the country, according to local custom the only ethical way to collect the flowers is by scavenging them off fallen tree limbs.

Of course, the black orchid is far from the only orchid in Belize, which also boasts such species as the Golden Shower orchids, nor is it the only beautiful orchid in the world. Yet as the national flower of Belize, it exhibits everything the Central American nation stands for: beauty, uniqueness, and a part of an ever progressing world.

Article prepared by Devin Windelspecht: Devin is a sophomore at Northeastern University in Boston MA where he majors in international relations.

Editor’s note: If you are ever in Belize, and want to experience a great collection of orchids, visit the Belize Bontanical Gardens at Ian Anderson’s Cave Branch Adventure Lodge. The black orchid photo above was taken during a trip in 2012 by the staff of RicochetScience and 5BlueMedia.