Is it a Fungus? Is it a Forb? No, it's a Tree!

Botanical gardens are sanctuaries for a northerner like myself. With winter fast approaching, the search for plants outdoors is coming to a close. Winter tree ID can only do so much for me during these times. As such, I try my best to make regular trips to tropical houses wherever and whenever I can. On a recent excursion to the Missouri Botanical Garden, I came across something completely unexpected.

I was perusing their tropical house aptly named "The Climatron."As I rounded a corner I happened to look down and saw what looked like something only a member of the birthwort family (Aristolochiaceae) could produce. There lying near the grown were a cluster of some of the coolest birthwort flowers I have personally laid eyes on.

I began searching for the plant that produced them. Up until this point, I have only encountered members of this family in the form of low-lying understory herbs and scrambling vines dangling from the canopy. There were no apparent leaves associated with these flowers and the part of my brain responsible for search images became confused. I traced the flower stems to their place of origin and realized they were attached to the nearest trunk. I followed the trunk upwards and realized that what I had found was in fact a small tree!

The species I was looking at was none other than Aristolochia arborea, a small tree native to the tropical forests of Central America. Needless to say I was floored. There is something to be said about any plant family than can vary this much in size and form. The coolest aspect about this tree is that, similar to the more herbaceous members of this family, the flowers are produced close to or directly on the forest floor.

A closer inspection of these strange blooms reveals an interesting morphology. It would appear that they are mimicking fungi in the genus Marasimus. Now this could just be a manifestation of apophenia. Was I seeing patterns where there are none? Of course, this was a job for scientific literature.

It is likely that I may have been on to something. Botanists agree that this plant is likely pollinated by fungus gnats and flies in the wild. However, no direct observations of this have ever been made. That being said, the flowers do emit a rather musty smell that could very well be described as "fungal." Regardless, this is an excellent choice of tree to showcase in a botanical garden. Stumbling into this species led me down an interesting botanical path.

Tree photo credit: Cymothoa exigua (Wikimedia Commons)

Further Reading:
http://florawww.eeb.uconn.edu/reference/arisarbe.htm

http://nature.berkeley.edu/brunslab/mycorrhizal/papers/kaiser2006.pdf