Poisonwood
Metopium toxiferum
By Roger L. Hammer
Have you ever considered planting a poisonous tree in your yard? As odd as that may sound , don’t forget that the leaves of the oleander can kill you if eaten. And let’s not forget poinsettia, lantana, dieffenbachia, fishtail palm, oyster plant and other commonly cultivated poisonous plants. Mangos anyone?
Anyway, if you are a real native plant aficionado, I think poisonwood, Metopium toxiferum, is as worthy as any other native tree for landscaping in southern Florida. Mature trees are sturdy, and the small, mustard-colored fruit are attractive to birds, especially to the endangered white-crowned pigeons that gorge themselves and their nestlings on the fruit.
Yes, the tree is poisonous, and the clear sap, which turns black when exposed to air, can cause a blistering rash similar to the related poison-ivy, Toxicodendron radicans. Other relatives of poisonwood include Brazilian pepper, mango, pistachio and cashew. Its not that I would suggest placing a poisonwood right out in your yard as a focal point or specimen tree, unless you’re even weirder than I am. Poisonwood would, however, be perfectly suitable for inclusion in a hammock re-creation, since that is its typical habitat, especially in the hardwood forests of the Florida Keys. It also occurs naturally as an invader in pine rocklands where it is kept shrubby by fire.
The compound leaves of poisonwood closely resemble gumbo-limbo, but a key diagnostic feature is that the leaflet midrib (central vein) of poisonwood divides the leaflet equally, whereas the leaflet midrib of gumbo-limbo cants off to one side. Poisonwood produces 3, 5 or 7 leaflets (usually 5), and gumbo-limbo produces 3, 5,7, or 9 leaflets (usually 7). Like Gumbo Limbo, poisonwood can mature into a rather large tree, and a classic example is the National champion poisonwood in Brickell Hammock (Vizcaya) that was measured at 90 feet tall prior to Hurrican Andrew.
This is not a tree that you will find in your local Home Depot garden shop. The tree in my yard came from the Florida Keys Native Nursery at Mile Marker #89 on Key Largo. And if you think you have to be mentally deranged to plant a poisonwood as a landscape tree, let me tell you about the manchineel tree in my yard.
Roger Hammer is a naturalist with the Miami-Dade Park and Recreation Dept.
This blog entry was taken from Miami-Dade Parks – Tropical Trails magazine Vol. 23 No. 2
Crandon Park Visitors and Nature Center 