In the spirit of spooky-ness, today I would like to introduce you to some of the most bizarre looking plants on our planet. I am of course talking about the genus Hydnora. Known locally as jakkalskos (jackal food) or bobbejaankos (baboon food), these odd parasites certainly look creepy. However, their ecology is downright fascinating and well worth a closer look.

Hydnora comprises roughly seven species and currently resides in its own family, Hydnoraceae. More recent taxonomic work suggests that this may actually be a subgroup within the family Aristolochiaceae, but as far as I know, the jury is still out on this. All species are native to southern Africa and as you can probably tell from the picture, they produce no leaves and no chlorophyll. Instead of wasting energy on producing its own food, Hydnora has resorted to parasitism. They are root parasites on members of the family Euphorbiaceae. They tap into the roots of their host plants using specialized structures called "haustoria." In this way they are able to gather all their nutritional needs from their host. Once a Hydnora has obtained enough energy it will produce a flower.

The flower is all you will ever see of this plant. The strange, scaly structure emerges from the ground underneath its host. Three slits begin to form, each lined with white, hair-like structures. At first these structures remain intact. The spaces between are just big enough to allow entry of pollinators, which in this case are dung beetles. Once the flower opens these slits it begins to produce some heat, not unlike what we see in many aroids. The heat helps to spread the scent and the smell is what you would expect from a plant trying to attract dung beetles - it smells like feces.

Photo by Charles Stirton licensed under CC BY-NC-ND 2.0

When a dung beetle arrives looking for some fresh poop, it enters the flower through those slits and falls down into the trap. The rest of the flower consists of a tube-like structure underground. To keep the beetles from escaping, Hydnora employs a trick used by many carnivorous pitcher plants. Lining the walls are downward pointing hairs that prevent the beetles from crawling out before their job is done. Once inside, the beetles are drawn to the center where the smell is emitted. Here they are dusted with generous amounts of pollen. If the beetles have arrived after a previous Hydnora visit then they will also deposit pollen and thus reproduction is achieved. Once the plant releases pollen onto the beetles, the hairs lining the wall relax and the slits open completely, allowing the beetles to escape.

I hope some day to see one of these in person. To the best of my knowledge, only a single species (Hydnora africana) has ever been grown in cultivation and that was a single event. Seeds were sown in a pot containing a known host species of Euphorbia. It took a very long time for germination and even longer to mature and produce a flower. Either way this creepy species is actually quite fascinating.

Photo Credit: [1] [2]

Further Reading: [1] [2] [3]