John’s been inventorying the Mariposa Cane Slough Preserve in Pt. St. Lucie, for which he produced an engaging slide show with great music. To keep the ball rolling, John and George sniffed around the preserve yesterday, enjoying nature’s oasis. CLICK
One end of Mariposa suffered a fire not so long ago, and the plant community there is different from the rest. There is a “lawn” of Gallberry (Ilex glabra). Gallberry is an example of our feeling that much of the fun of botany comes from getting to know the everyday plants. Often that’s especially fun because we see the everyday plants, well, every day. If you have ever tasted the black pea-sized fruits you know why it is called “gall” berry. They are bitter, although in sort of an interesting way. Birds and wildlife don’t all find them too bitter. Maybe the intense flavor discourages the “wrong” fruit-eaters.
There’s a lot of weird stuff about Gallberry, beginning with the fact that it is a Holly. If this is not clear at first glance, the flowers are Holly-ish, and leaves look like those of small Asian Hollies used in landscaping. To steal a 1974 quote from horticulturists Jack Alexander and Michael Dirr, “If Gallberry came from Japan, people would rave about it.” Of course, the U.S. was especially fascinated with Japan in the 70’s. Fact is, there are several named horticultural cultivars of this species, more valued up north than in Florida. Up north?
How many species do you know with a distribution from Florida all the way to Nova Scotia (and westward to Missouri)? The breadth of the distribution underscores the environmental breadth of Gallberry: hot, cold, sunny, shady, acid, slightly alkaline, clay, sand, or salty. The species prefers moist sites, although there is drought tolerance. The diverse Florida habitats include low pine woods, especially after fire.
The most interesting features of Gallberry have to do with fire. Here is a hot quiz question.
What do mushrooms, many grasses, icebergs, Gallberries, and spy syndicates have in common? Answer: Most of the action is hidden below the surface.
Gallberry rhizomes and roots form a massive widespread subterranean network. The rhizomes can grow to multiple inches in diameter and can run several feet underground connecting bush-with-bush-with-bush like stations along a railroad line. This helps explain why Gallberry can form a monospecific even-aged “lawn” of thousands of individuals. As with the Hydra of mythology, cut off one head and is sprouts more.
Who would cut off the head? Fire mostly. Easy to envision here in flammable Florida, although it is fun to wonder if fire is the only leveling force to mow down the Ilex from here to Nova Scotia (or wherever the species evolved originally—see below). Maybe grazing by herbivores, or extreme cold, or other harsh forces of nature have been factors in the equation too.
Have you ever noticed how a patch of Gallberry can be nearly or entirely berry-forming or not? As a Holly, Gallberry is dioecious, that is, with separate male (pollen-producing) or female (fruiting) plants. A big patch, all growing from the same rhizome network can be one big individual genetically speaking, just like a mushroom “fairy ring.” Such a patch could be all male or all female, although more than one rhizome-individual might establish in one patch, especially given the prolific fruit production and assistance by berry-eating birds and mammals. If the patches were too unisexual and too separate there’d be no cross-pollination.
While on the theme of Hollies, did you know that Hollies are among the few plant groups with drinkable caffeine? Hollies serve as teas in scattered regions, including the “Black Drink” consumed by Native Americans in the Southeastern U.S. derived from Dahoon Holly and from Yaupon Holly, and the Yerba Mate sipped at South American tea parties. What about Gallberry? Some folks call it “Appalachian Tea,” although its caffeine levels range from zip to bitsy.
One final odd tidbit. Multiple species of Ilex (Hollies) are native in the U.S. And you might naturally expect species found together to be most closely related to each other, which is often so but not here. DNA study shows Gallberry a member of a species cluster otherwise limited to Eurasia and Africa.
Did a migrating bird bring it? Or with its northern predilection, did the distribution once sprawl from Asia, across a once-dry Bering Strait leading to sunny Florida? There are many florisitc links between eastern Asia and the eastern U.S. In any case, the 1974 comment invoking Asian landscaping Hollies was more true than the authors knew.
In short then, here’s a shrub we trip over rushing through the forest looking for the rare or noteworthy, while this humble shrub is notable in its own right as a valued landscape Holly, as a rhizome champ, as a natural shrubby “lawn” after fires, as a native cafeteria for wildlife, as a half-hearted tea, and as an Old World species far from home. Perhaps it did come from Japan, and it is ok to rave.