You can scarcely find a group of trees more steeped in American lore than hickories, but let’s not be American-o-centric in the era of globalization. Hickories are native to China, Viet Nam, and Laos too, being examples of the sister-species relationships linking Eastern U.S. and East Asia. I wonder if there’s a Euell Gibbons-type guy in China who savors wild hickory nuts there.
The best hickory nuts are Pecans, cultivated in the southeastern U.S., and speaking of China, likewise there. We even have some cultivated in Palm Beach County, although the native region is somewhat farther north. The native range of Pecans is actually somewhat unclear, thanks to ancient peoples’ taste for the nuts. I’ve seen them growing wild in lowland woods along the Mississippi River.
The name Hickory comes from an Algonquin word for a milky paste made from pounding the nuts.
Hickory wood is ultra-strong, durable, and snappy-bendable. They used to make golf club handles from it, and hickory clubs are enjoying a little retro-chic nowadays. Today I read a (1936) article on how to select the strongest hickory hammer handle. There is hickory flooring and hickory furniture. Pre-Europeans and modern bowyers could debate whether hickory is the best wood for archery bows. (Osage Orange and Yew would have loyal proponents.) The list of hickory products could go on. In addition to tasty nuts and tough woods, hickories are beautiful. I’ve spent a lot of time in the Appalachians and in the Ozarks, and life just wouldn’t be the same hickory-less.
The good news is that here is South Florida, contrary to all that “tropical paradise” nonsense, we have two lovely hickories: Water Hickory (Carya aquatica) and Scrub Hickory (Carya floridana). The two names hint at the interesting part of today’s topic. Our two hickories couldn’t be farther apart ecologically. Water Hickory lives up to its name by being a soggy shore and swamp species. (A great place to see them locally is Riverbend Park in Jupiter.) Its natural range is across the southeastern U.S.
Or if sun-baked sugar sand is more to your liking, Scrub Hickory is the one for you. This odd tree lives in high dry scrub, where it can be the dominant (or only) broadleaf tree. Its distribution is limited to the Florida Peninsula.
You might wonder if two species found jointly down here in South Florida are close relatives. No. They are in separate sections of the Hickory genus Carya. Water Hickory is related to and hybridizes with Pecans, which are naturally a swampy species. Scrub Hickory, by contrast, is related to the common widespread Pignut Hickory (Carya glabra), which lives (among other habitats) on high dry “scrub-ish” places.
Time to speculate. Carya aquatica is a widespread species that probably wandered from the more northern states into Florida in ancient times. The history of Carya floridana is more fun to imagine. It is restricted to Florida and probably evolved here. Most of Florida has been inundated too recently to have much ancient evolutionary history, except on scrub which differs from the rest of Florida by having been high and dry vastly longer then the lowland regions favored by Carya aquatica. Scrub has been high and dry long enough for plenty of evolution. Now to repeat, this is speculation, not fact, but Carya floridana perhaps originated on scrub as an isolated southern satellite population of Pignut Hickory, Carya glabra, which is variable and widely distributed in Florida, although not this far south. Florida scrub areas were figuratively and literally islands as sea levels rose and fell over the eons, the perfect setting for an isolated splinter-group from a more broadly distributed species to evolve into a separate species in its own right. Interestingly, these two species (and some other related hickories) have the same tetraploid (doubled) chromosome number consistent with close relationship.