Friday, January 7, 2011

Chinkapin's story

I always say that every individual oak tree has a story to tell us.  Same goes for species, and for once I won't use the obnoxious quotation marks I always use when associating the term species with oaks.

The more I learn about chinkapin oak (Quercus muehlenbergii) the more fascinated I become, and the more I want to know its unique story as a species.

Miller and Lamb's Oaks of North America is divided very neatly into two sections, one for east of the 100th meridian, and one for west of the 100th meridian.

(Little reminder, more for me than for you, of where the 100th meridian is located.)
It can be divided neatly along the 100th meridian because of the simple fact that no oak occurs on both sides of that line, except one:  Chinkapin oak.  Predominantly an eastern oak, its range slices diagonally into central Texas and then... nothing.  No more chinkapin oaks for hundreds of miles heading west, until you find isolated islands of them in Trans-Pecos Texas, southeastern New Mexico, and northeastern Mexico.

Samuel Lamb writes in the introduction to the "Oaks West of the 100th Meridian" section of Oaks of North America:  "The breadth of the Great Plains has been a barrier to the spread of plant species for a long time.  When the sea subsided from the large area of the Midwest, the tree species from the East and the West were not able to migrate across the wide expanses, so the eastern species remained in the East and the western species remained in the West.  The same general rule applied to oaks, except for chinkapin oak, Quercus muehlenbergii.  This oak must have ranged across the plains, as there is still a remnant population in west Texas and in New Mexico."

So at one point in the mists of time the range of chinkapin oak extended contiguously through Texas into New Mexico and Mexico, and then receded due to climatic changes, leaving remnant populations where the local climatic conditions - rainfall, elevation, aspect, soils - were favorable, or at least favorable enough, for a few pockets of chinkapin oaks to remain.  For now.

I plan to spend a lot more time looking at the unique case of the chinkapin, but I think it's probably only "unique" in that it's happening now, but is simple a repitition of a pattern that has played out countless times throughout the history... of history.

I wonder if anyone has bred any of the remnant chinkapins west of the 100th with their eastern brethren? 

According to Lamb, in the "western extension" of its range only one hybrid with chinkapin oak is listed - Quercus x (no name given) (Q. muehlenbergii x gambelii).  No name given? Usually dudes are dying to get their name, or as we have seen, their girlfriend's name, on the latest hybrid.

Well I can solve that.  It is now Quercus x siemsii.

So that's that problem solved.

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