Indian Grass 2012

This is the time of year to enjoy the tall grass prairie.  The Indian Grass at Blue Jay Barrens has reached its peak for the year and will get no taller.  It’s a joy to go out and get lost among the towering grass stalks.

The grass is looking particularly healthy this year.  Winds associated with passing weather fronts move the grass in waves across the field.

Despite its apparent vigor, the grass has behaved oddly this year.  Stalks from last year’s stand are still present.  Early summer rains normally cause the base of the dead stalks to decompose.  The stalks then topple.  By summer’s end, the stalks are hidden from sight.  The intense early summer drought kept things so dry that the old stalks never fell.  In the shot above, the area in the foreground was mowed during the winter, so all of the stalks were cut and laid down.  The area behind was left untouched and the light brown of old stalks is clear to see.

The second thing of note this year is the height of the grass.  Bluebird nest boxes should now be hidden by the grass.  The top of the nest box is right at five feet above the ground.  Most of the grass falls well short of that height.  The tall grass experience is just not the same when the grass just barely makes it up to your shoulder.  Not much chance of getting lost in grass like that.

A rain storm during grass bloom provided conditions that were just perfect for pollination and seed set.  Despite its short height, the grass produced normal sized heads.  I’d say that the grass had a successful season.

Unlike last year’s staggered ripening schedule, the Indian Grass this year is all developing at the same rate.  Everywhere I checked I found developing seed at the milk stage, meaning that the center of the seed contains a white liquid.  It won’t be long before the seeds harden and begin to turn brown.  It appears that sparrows spending the winter in the fields will have plenty of grass seed on which to feed.

Flowering Indiangrass

Things have been out of sync all season at Blue Jay Barrens. Both plants and animals have failed to perform annual events within the normally accepted time limits. Now, several weeks later than normal, Indiangrass has burst into flower.

Indiangrass has wind borne pollen that adds to the aggravation of seasonal allergy sufferers. Spiders trying to maintain their webs in the tall grass have to cope with a continual buildup of pollen on the sticky strands.

Some Indiangrass plants bloomed at their expected time and are now developing seed. In a few places entire patches flowered in unison. In others, only scattered plants produced flowers. This is the opposite of what happened last year at this time when most of the grass had passed flowering and only a few isolated patches and plants were blooming.

I had plans to harvest some Indiangrass seed to help with a local prairie restoration project. The massive delayed bloom means that ripe seed won’t be available as early as I had anticipated. This could be a problem if we have a rainy fall.

It’s nice to have a few mowed trails when the grass gets like this. My off trail excursions through the Indiangrass have left me covered in yellow dust. When it reaches the point where everything I look at is yellow, I know that it’s time to clean off my glasses. This is the way I would expect the grass to look around the third week of August, as it did in 2009.

Sometimes even a mowed path doesn’t help. Tall plants rely on support given by their neighbors in order to remain upright during windy or rainy conditions. Without that support, the tall plants begin to lean. Even a six foot wide path can be quickly blocked.

Migrant dragonflies maintain a constant patrol above the tall grass. It’s not until evening that they come down to roost overnight in the tall grass. Dozens of these Common Green Darners can be seen over the field at any one place.

Indian Grass

The dominant tall grass at Blue Jay Barrens is Indian Grass, Sorghastrum nutans. This is the time of year when most of the prairies are transitioning from wildflowers to grasses. Many of the flowers that were evident just two weeks ago are now hidden by the rapidly growing grass.

Indian Grass is now flowering and this makes it very conspicuous in the fields. Final height is usually around six or seven feet. This is tall enough to effectively hide any animal that might wander through.

The flower head is very loose and open. As the flowers are fertilized and seeds begin to form, the spikelets or side branches of the flower head will become more aligned with the central stem so that the seed head is more dense. If picked and dried just as the seeds mature, the seed heads make wonderful additions to dried flower arrangements.

The yellow color of the flowers comes from the exposed anthers. The white brush-like features are the stigmas. Once pollination has occurred, the seed heads will take on a golden brown appearance.

One of the identifying characteristics of Indian Grass is the rifle sight ligule of the leaf. Pulling the leaf gently away from the stem will bring this feature into view. The size and shape of the notch is variable.

This field is in for a lot of changes over the next few weeks. The Indian Grass flower heads will change from yellow to brown as the leaves take on a darker shade of green. Finally, frost will rework the whole scene to a bright golden brown.