|Image 1. Ammophila breviligulata in center|
Assateague Island straddles both Maryland and Virginia. It is a narrow barrier island that I visited and hiked this month, and it contains several ecological areas that made it quite diverse when it came to species diversity. Click here to look at a map of the island.
|Image 2. Panicum amarum|
|Image 3. Ammophila breviligulata (left) and Panicum amarum (right)|
Their inflorescences are very different as well, as you can see in Image 4 below. A. breviligulata has a whitish spike like inflorescence, while P. amarum has the typical Panicum type spikelets,
|Image 4. Ammophila breviligulata (left) and Panicum amarum (right)|
As I continued hiking inland into the marshes I came upon the second layer, which is actually composed of several sublayers (see Image 5 below). The area of the marsh closest to the sea (the low marsh) is inundated daily and has higher salt concentrations, and this area was dominated by Sporobolus alterniflorus (Spartina alterniflora). The so-called "high marsh" is farther away, is not inundated all the time, and is less salty. Here I found Sporobolus pumilus (Spartina patens) and the graminoid Juncus roemerianus, which is in the rush plant family and is NOT a grass.
|Image 5. Marsh|
It was fairly easy to tell the two grass species apart. S. pumilus has wavy looking blades that look quite beautiful and distinctive. In the image below (Image 6) the species looks almost like a nice soft fluffy lawn.
|Image 6. Sporobolus pumilus (Spartina patens) in foreground (NJ pic)|
Sporobolus alterniflorus is more erect in form, and it forms the vast bulk of the vegetation that people associate with marshes as they drive towards the beach. The geometric shapes of their vast stands was quite pleasing to the eye, and I spent some time taking various artistic pics of the scenery.
|Image 7. Geometric stands of S. alterniflorus (S. alterniflora) in the background|
|Image 8. Inflorescence of S. alterniflorus (S. alterniflora)|
Beyond the marsh layer was a forested area, but also pockets of large meadows. This most inner layer is surrounded by the beaches and marshes, and I was astonished to find some species that I would never associate with islands.
Next to the trail were rows of what I believe were Schizachyrium scoparium (little bluestem), and behind them the beautiful panicles of Panicum virgatum (switchgrass) waved in the breeze. Farther back were dense stands of the invasive Phragmites australis (common reed), which also was present in the high marsh.
|Image 9. Meadow layer with a series of grass species|
|Image 10. Microstegium vimineum|
Nevertheless, I really enjoyed visiting and hiking the short trails in the island, and I loved the structured layering of these major grass species throughout the area.