The beech orange, likely Cyttaria darwinii. These were sprouting near Ushuala in southern Argentina. Image courtesy Bruce Muller; used with permission.

The Southern Hemisphere's collection of alternate-universe creatures is not limited to emus, echidnas, and monkey-puzzle trees. There are also crazy down-under fungi. And one of them was first encountered and collected for science by none other than the Big Man himself: Charles Darwin.

Darwin was on his course-of-western-history-altering Beagle cruise when he was probably captivated (or at least momentarily arrested) by the odd appearance of Cyttaria darwini, the "beech orange", in Tierra del Fuego. This fungus grows in association with the southern hemisphere genus Nothofagus, the "southern beeches", and it is not subtle in going about it.

A cluster of Cyttaria harioti and its gall on a southern beech. Creative Commons Fermar; click image for license and link.

The fungus releases chemical signals that cause the tree to form a gnarled gall that sustains the fungus, from which it sprouts perennially in spring or summer. Since its host trees are restricted to the southern hemisphere, so is the fungus, making it an honorary member (the club is supposed to be restricted to plants) of the Antarctic Flora. These are the descendants of the plants that evolved on the ancient supercontient of Gondwana that are now broadly distributed across the Southern Hemisphere thanks to 180 million years of continental drift.

Image courtesy Bruce Muller; used with permission.

After shooting its spores, the beech oranges drop from the tree, while the gall remains. Although heavy infestations can kill branches, the fungus doesn't seem to rot wood or generally cause its host any serious harm. It may even offer its host a benefit of some sort. As a result, it may be a parasite, commensal, or even mutualist. It's often a grayer area than you might imagine.

Cyttaria is a member of the huge group of fungi called the ascomycetes. As we've seen here before, these are fungi that bear their spores inside sacs called asci ("ass-eye"). They often forcibly shoot them out of these sacs as a way of booting the next generation out of the nest. Many ascomycetes produce their asci in cups, and in the case of the beech orange, the cups are the orange dimples of the golf ball. They're analagous to the honeycomb cups on the head of a morel mushroom.

Species of Cyttaria can be found not only in South America, but also Australia and New Zealand. Native peoples in both hemispheres seem to have considered beech oranges at least palatable. A related species of beech orange, C. gunnii, occurs on southern beeches in Australia and New Zealand. In Australia, too, aboriginals consume the fruiting body.

Darwin himself noted they made up a substantial portion of the diet of the natives of Terra del Fuego and grew "in vast numbers on the beech trees". He observed that the women and children collected their beech oranges when "tough and mature", and that they had a "mucilaginous, slightly sweet taste, with a faint smell like that of a mushroom." What the taste of mucilage might be I leave to the reader's imagination.

Another South American group -- the Araucans of Chile -- discovered and capitalized upon the happy fact that Cyttaria harioti contains up to 15% fermentable sugars and that, like grapes, come naturally coated with the yeast Saccharomyces. This would be the same Saccharomyces that has made the fortunes of Fleischman's, Budweiser, and half of France.

After drying, grinding, and mixing beech oranges with warm water and allowing nature to take its course, the Araucans enjoy an alcoholic beverage called chicha del llau-llau made from the ripe fruiting bodies, according to Bryce Kendrick's The Fifth Kingdom. No word from Kendrick on the beverage's bouquet, body, or "smooth drinkability".*

According to the Royal Botanic Garden at Kew, Darwin sent his specimen to the eminent mycologist the Rev. Miles J. Berkeley**, who identified it and subsequently named it after him. It lies at Kew today, and if you had the right credentials, you could examine the very specimen he collected.

One final note. Although to our eyes (or at least mine), beech oranges scream golf ball, Darwin or even Berkeley would not have recognized them as such. Though golf was being played in Scotland as early as the 15th century, dimples weren't added to golf balls until 1905.


* Could this be the next big thing in MicroMycobrews? "No plants necessary. This brew is 100% Kingdom Fungi."

**According to Bill Bryson's book At Home, the 18th and 19th century British clergy was the source of many de facto scientists due to the profession's winning combination of a comfortable salary with a job that demanded relatively little in the way of actual work (one sermon a week seemed to be the minimum effort required, and books of stock sermons could be purchased and employed for those who were otherwise preoccupied). Many clergy found this a way to subsidize a highly profitable -- though technically unofficial -- career in science.