Tuesday, December 28, 2010

Texas - where oak ranges are small (and Muller was busy)

We just looked at Georgia and South Carolina's Oglethorpe oak, a dubious "species" with all the earmarks of a hybrid and a range you can throw a rock across.

Well for tiny ranges and dubious oak taxonomy, there's no place the the Big Bend region of Texas.  And there's no taxonomist like C. H. Muller.  About whom I know nothing and whom I am about to disparage for no good reason other than my own amusement... well that and to make, for the jillionth time, a point about the ridiculousness of our understanding and classification of oak "species."

Coahuila scrub oak (Q. intricata Trel.) - range consists of 2 tiny dots, one in Big Bend and one to the NW of that.

Mexican dwarf oak (Q. depressipes Trel.) - range is one tiny dot half way between the two dots of Q. intricata.  The description says "half evergreen."  That's a bit like half pregnant - either than or a line from the Yogi Berra of oak taxonomists: "Ninety percent of these trees are half evergreen."

Who was Trel. and why didn't he/she get his/her full name associated with these species?  By contrast, let's see how a master does it:

Hinckley oak (Q. hinckleyi C. H. Muller) - range is a tiny dot to the north of Big Bend.

Vasey oak (Q. pungens var. vaseyana  (Buckl.) C. H. Muller) - another "half evergreen" with a larger range than actually spans county lines

Chisos oak (Q. graciliformis C. H. Muller) - starting to spot a trend here?  Mr. Muller was namer.  This one is not a half evergreen.  Nosiree.  This one is "partly evergreen."  Which is, of course, completely different than half evergreen.  Just don't ask me how (although in the comments you're more than welcome to tell me how!).  Its range consists of two tiny pin pricks, one in Big Bend and one just across the Rio Grande in Mexico.  Hybrids?  There's one.  I'll give you one guess as to who identified it.  Right you are!  Quercus x tharpii C. H. Muller (Q. graciliformis x emoryi).

Lateleaf oak (Q. tardifolia - Ta Da! - C. H. Muller) - range: two clumps in the Chisos Mountains in Big Bend.  Two clumps?  I'm guessing two trees.

All of which makes me very happy I studied forestry here in Minnesota where we have six (seven if you count that one chinkapin oak down in Houston County) oaks, thus limiting the number of possible hybrids to about 4 dozen.

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