Monday, February 18, 2013

The next phase: Stem Elongation, or Jointing         

Our wheat has been growing for three months.  More or less.  It germinated in those December rains, and demonstrated prominent leaf growth, with our Sonora showing three leaves in the first month and two or three more since then.

In fact, leaf-making (and the more hidden root development) is about all that seems to have been happening.


So far, essentially all of the plants’ height is created by the leaves, whose sheaths roll and curve around each other in a telescoping tube, forming a hollow column called a pseudo-stem.  (Not to be confused, I guess, with the real thing.)

Though made up of thin, leaf-like material, the pseudo-stem’s strength and erect stature is like a sheet of typing paper which has little stability if set on edge, but can be quite sturdy when rolled into a tight tube.         

The main plant itself has been holding back, waiting until it knew those leave and roots would be able to sustain it.  Then we were expecting that the wheat plant would launch into its third major growth stage:  Jointing.

My impression was that this jointing or stem elongation was reasonably straight-forward.  The plant gains height as the space between the leaves lengthens.  Maybe more leaves appear.

  Simply stated, the wheat would get taller. And we could look on, as we do with our kids, marking their increasing stature on the kitchen doorway woodwork.

 But a lot more of the process was taking place out of the public view.  During jointing, the embryonic seed head would make its way upward, within the hollow pseudo-stem, heading from ground level up toward eventual emergence into the fresh California air where we hope it will ripen into harvestable grain. 

 And a blog from a soy bean and wheat specialist at the University of Wisconsin opened up a whole new vision.  He made it look simple to slice the plant stem and reveal the tiny hidden seed head that is one of the hidden marvels of wheat.  It's called the Inflorescence, and he described it as a dark green pine-cone shape, with tiny beads, suggestive of the spikelets that would bear potential wheat kernels.

So the exacto knife came out and I began serious surgery on the 1/16th inch wide stems of two month old plants from Maggie’s Farm.  But the results were disappointing, a lot like my first middle school science class when Mrs. Lewisham kept insisting that the microscopic view of the Petri dish was more than a gray blur.

Those first cuts were all near the crown at the base of the plant, right at the soil level since I thought the jointing process had yet to begin.  Success finally came when I made my slice higher up on the plant.  Bingo."

This intricate shape which is making its way up the stem is called the Inflorescence.  The flowering of a plant, often a process going from simple elements to quite complex blossoms that lead to fruiting.

And so this is the big news:  our wheat is well on its way, with that microscopic wanne-be seed head as much as halfway up the pseudo-stem, past leaves one and two, and sometimes past three.

Extreme close up of the elements comprising a wheat inflorescence.
The longest of these little rascals, head-to-tail, is one-quarter inch.

It’s on the march, the leaves and roots supporting its advance through all the leaf sheathes, until it emerges from the final, or Flag leaf.  And, unlike all the other leaves, each of which housed another emerging leaf, that Flag leaf has only one thing up its sleeve – a miniature seed head. 

And that seed head will finally emerge into the air, swell a bit, break into flower, each grain being pollinated in a dalliance with nearby anthers, and be on its way – in about a fortnight – to maturity as a full fledged head of tasty kernels.

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