Cycad Sex

I’ve always had a fondness in my heart for cycads.

Encephalartos princeps

Years ago, while working in the Ituri Forest (in what is now the Congo), I kept hearing of a particular place in the forest, where the Efe Pygmies would occasionally but not often go for various reasons. Over time I asked about this place, and eventually made arrangements to visit. My first trip to what was known as the Kakba was a very long and difficult walk from a camp that was already about a day into the forest from the villages, where our research base camp was located. On approaching the Kakba, it was obvious to me that the habitat we were in … rain forest … was giving way to something else. The trees, for one thing, were more sparsely leafed out. We were in the middle of the “little dry season” and it seemed that as we climbed very subtly in elevation, we encountered areas where there was little or no groundwater, and the underlying granitic basement rock was right on the surface. The rain forest trees were still present, but more spread out and clearly water stressed.

A Repost

Then these trees gave way to different trees. These were trees that one did find here and there, but in this location, they were abundant. These, in turn, gave way to increasingly large patches of grass … actually open areas that were about half grass and half exposed granite surface. I later came to learn that some of these granite surfaces would be covered almost entirely with grass, then exposed, in both seasonal and inter annual cycles, depending on factors such as how long and dry the dry season was, and erosion from servere storms.

It was also notable that the animal sign changed entirely. Instead of seeing mainly footprints of small forest antelopes, I was seeing footprints of elephant, forest hog, and, remarkably, baboon.

Encephalartos natalensis

Then, the brushy woody vegetation mixed with open grass patches gave way to a cycad forest. Most of the medium to larger plants were cycads, giant prehistoric looking fern-like (but not ferns!) plants, 12 to 16 feet tall, with giant seed heads about 4 to 6 feet long, growing out of these strange serpentine trunks that ran along the ground for hundreds of meters, with these big plants sprouting out of them now and then.

I had arrived about the time that the seed heads were ripe, and they were ripped apart by baboons who heartily fed on them. The Efe I was with, of course, were really pissed at the baboons, because the sparse flesh found on each seed is edible, and these guys were hoping for a meal.

I ended up doing a lot of research in and near this cycad forest, although not so much on cyads. The area also has rock shelters occasionally used by the Efe, but in the past, much more often used. Archaeology done in this area later by Julio Mercader has demonstrated that Pygmy-like people have lived in this rain forest for several thousand years, while the area was still very much forested, but well before horticulture came into the area, thus disproving Bob Bailey’s rather snooty hypothesis put forth in the early 1980s that humans could never live in a rainforest without access to agricultural products.

Anyway, here’s some interesting research on cycads, just out:

University of Utah scientists discovered a strange method of reproduction in primitive plants named cycads: The plants heat up and emit a toxic odor to drive pollen-covered insects out of male cycad cones, and then use a milder odor to draw the bugs into female cones so the plants are pollinated.

The unusual form of sexual reproduction used by some species of cycads — primeval plants known as “living fossils” — may represent an intermediate step in the evolution of plant pollination, the researchers report in the Friday, Oct. 5 issue of the journal Science.

This is from Science Daily … at some point in the future I may expand on this, after I’ve read the original research, though it is not really my field.

But do enjoy these photographs of cycads I took in July, in Kirstenbosch Gardens, near Cape Town, South Africa…

Encephalartos friderici-guilieimi


  1. #1 een
    October 6, 2009

    Careful with that cycad – I believe a lot of them have poisonous seeds, which can cause weird neurological symptoms. Cattle in Australia used to get paralysis from grazing on a species there, and I believe some people in the South Pacific have suffered symptoms very like Alzheimer’s (sp?) disease. Presumably the flesh of the fruit is OK if the wildlife and the locals eat it, but still…

  2. #2 Rob Halpern
    October 7, 2009

    Terrific tale. Thanks.
    I’d like to pick up the story for my site on amazing plants, plant/animal relationships, medical botany, etc.: