Although never common, bunches of Joint-tail Grass can be found in south Texas along creeks and streams where livestock are not grazing.  Joint-tail Grass is related to teosinte, the precursor of modern corn, and shares many of its attributes.  This specimen was found along Medio Creek in Bee County.  Here you see a close-up of the two-pronged seedstalk.  It is a woody spike with the seeds inside small cavities, one seed per joint.  These spikes break apart at the nodes as part of the normal process of scattering the seeds.   Robert Benson photo.

Identifying LBBs and Odd Grasses.  As a naturalist I feel that I am expected to know how identify everything.   But of course this is impossible.  The best a naturalist can do is to know a little bit about everything in general.  And hopefully, each naturalist knows a lot about something.  In other words, we naturalists specialize in some aspect of nature.

Some of us specialize in birds, others know botany well, some focus on insects, and a crazy few specialize in scat.  This last one is not my specialty; all scat looks like poop to me!

I think my specialty is bird identification.  I have spent many years learning the birds and their field marks.  Even so I still cringe when someone asks me, “What is that little brown bird?”

My usual answer, “Er…hum.  A sparrow?”

Now that might satisfy the incurious person, but most people want to know what kind of sparrow.   There are over 40 species of sparrows in North America.  And they all come in various shades of brown.

Identifying south Texas sparrows is hard.  But once you learn them, you’ll be proud of your ability.  It’s best to start with the easy ones like this Lark Sparrow.  It is common in the hedgerows and fields of the brush country.  It is the only sparrow with a showy harlequin face pattern, an unstreaked breast, and a spot just below its throat (the stickpin).  When it flies, it shows white spots on the corners of its tail.  Robert Benson photo. 

Sparrows are hard to identify.  Birders tackle sparrow identification last as they learn their birds.  These little brown birds (LBBs as I call them), take a lot of practice.  But it can be done.  Look at the bird-in-question’s breast and then its head.  Look for patterns and plainness.  By this method you can usually narrow down an LBB to a species.  Good luck!

Grasses are even more difficult to identify than sparrows.  Grasses are green, and unless you find them in flower or with seeds, they really all look alike to the uninitiated.  At least they do to me.  But I am working on learning grasses.

I can ID johnsongrass (big with yellow mid-veins and an open, reddish panicle) and inland seaoats (midsize, grows in shade, and has a side-drooping panicle with flat spikelets).  Also, these two are pretty easy to figure out using pictures.

It’s the vocabulary that gets me.  I mean, what exactly is a panicle, a spikelet, a lemma, or a glume?

I’ve learned that a panicle is a branching seedhead.  The individual seed with its wrappings is called the spikelet.  Glumes and lemmas are those wrappings (I think).

So when I came upon a new grass in the bottomlands of our South Texas creeks, I knew it wasn’t johnsongrass or inland seaoats.  No panicle.  Instead there was a two-pronged seedstalk (called a spike) sticking out of the top of the grass. 

The spike was cylindrical, woody, and had nodes (joints) about a half inch apart.  When I touched the spike, it broke apart at the nodes!  I examined my handful of the sections and realized each one had a groove leading to a small hole on one side.  Cutting one open I found a single seed nestled in a hollow inside the section of stalk.

This grass was Joint-tail Grass (Coelorachis cylindrica).  I think it is pretty cool how its seeds were protected inside the stalk.  A wind or a brush with an animal would break the little joints off.  A rain could carry them to a new location. 

Joint-tail Grass is found in the southern states, but it is not too common anywhere.   I read that it is quite palatable to livestock.  If grazing animals find it first, you’ll never see it.  But the joint may protect the seed while it passes through the digestive tract of the animal.   It can then be deposited, along with a bit of manure to fertilize it, in a new home.

The most fascinating thing about Joint-tail Grass is that it is very similar to teosinte, a wild grass from Mexico.  Archeologists think it has been in cultivation for over 10,000 years.  Teosinte is believed to be the ancestor of modern corn.

Wild-type teosinte seeds are enclosed in a hard case formed from the seed stalk.   Over 4,000 years ago, Aztecs in central Mexico discovered a mutation in their fields of teosinte.  The seeds were only partially covered by the hard case. The new teosinte kernels were attached to the side of the stalk and were much easier to extract for food.

 They selected these and planted them instead of the hard case variety.  Thus they moved the evolution of corn forward greatly.  Modern geneticists have discovered that a single gene was responsible for this change.  It seems that only five genes were involved in the transformation of teosinte to modern corn.  It is very likely that each genetic change was selected for by humans growing teosinte for food.  Corn was, and is, a staple in the human diet.

No wonder the Aztecs called it teotl + cintli in the Nahuatl language.  “Teotl” means God, and “cintl” means dried ears of maize.  Did that translate as Corn of the Gods?  Or perhaps it meant the Corn was a God.

Food and culture writer, Michael Pollan, suggests that corn is actually using us humans as a means to dominate the world.   Over the centuries of improvement, corn has manipulated us to plant it over millions of acres, to be dependent on it for food and related products, to genetically modify it so that it makes its own insecticide.   Maybe Pollan is right.  Corn is rapidly becoming King Corn.

So from humble Joint-tail Grass here in South Texas, we connect to one of the most widely grown crops in the world.  Interesting, no?