A visit to saline/alkaline sites near Summer Lake, Oregon
Saline/alkaline soils support a different community of wetland grasses: ones that can tolerate or thrive under conditions of periodic inundation, high pH and high concentrations of various salts. These conditions are found together in the internally drained basins of the Great Basin region, which extends into southeastern Oregon. Internally drained means that there is no stream or river flowing out of the basin; the water goes "out" by evaporation into the air, leaving the minerals behind.
Summer Lake itself is dry in September, but the Summer Lake Refuge has extensive wetlands managed for waterfowl. Some of these shallow wetlands are saturated for only part of the season. The margins of the ditches and shallow lakes, as well as the areas that dry out in summer, support a variety of grasses that tolerate saline/alkaline soils.
Saltgrass along the road
Greasewood in the foreground.
Saltgrass (Distichlis spicata) could be considered the signature grass of this habitat, growing with a number of associates, including greasewood (Sarcobatus vermiculatus). Saltgrass is easily recognized by a number of distinctive characters: the scaly rhizomes, the stiffly spreading, 2-ranked leaves and separate male/female plants.
The leaves are described as 2-ranked and stiffly spreading, which is the meaning of "spicate" in the specific epithet: spicata.
By definition, rhizomes are below-ground stems. Barbara Wilson maintains that grasses don't read the books, so sometimes rhizomes come topside, like in this example.
Female saltgrass plants.
To read more about saltgrass click here
Common Reed (Phragmites australis)
Common reed is far and away the tallest grass in this habitat, growing well over a couple of meters high. It commonly grows at the edge of canals, ditches, or other open water. Phragma is the Greek word for fence, referring to its fence-like growth (or maybe that its culms are stiff enough for fencing material).
There are both introduced and native subspecies in Oregon and can be distinguished by the lower culms. If you top-snatch this one, you won't be able identify it to subspecies.
Spikelets of common reed have 2-10 florets with long silky hairs on the rachillas that allow the seeds to float away on wind or water.
Alkali Grass (Puccinellia )
Two species of alkali grass grow at Summer Lake Refuge: Puccinellia nuttalliana and P. lemmonii. The taller one is Nuttall's and the shorter one is Lemmon's.
Puccinellia nuttalliana in a sea of saltgrass. Note the jagged edge on the upper third of the lemma. This character distinguishes the alkali grasses from bluegrasses (Poa).
As in other grasses, the panicle branches spread at maturity by the use of a pulvinus, the little bulge at the axil of the panicle branches.
Rabbitsfoot grass (Polypogon monspeliensis)
In this Polypogon species, the glumes have long awns and spikey hairs. There is just one floret per spikelet.
This widespread annual grass is native to southern Europe and Turkey. It is frequently found in disturbed wetlands and ditches, often on alkaline soils.
Foxtail barley (Hordeum jubatum)
This lovely native grass thrives in alkaline lowlands that are saturated in the winter and spring. The spikes have three spikelets per node, of which only the central one is fertile. Lemmas are awned and glumes are awn-like and it all comes apart at maturity. Thus, this grass is not a favorite of cattlemen and you don't want to collect its spikelets in your socks.
Alkali Muhly or Scratchgrass
Alkali muhly growing on the edge of the water with its friends, saltgrass and foxtail barley.
The airy open panicles of alkali muhly break off at maturity and float away on the wind or water to scatter its tiny seeds to new locations. Spikelets are only 1-2 mm long and usually contain only one floret. In contrast the base of the plant is anchored with coarse scaly rhizomes.
Tall and intermediate wheatgrass
(Thinopyrum ponticum and T. intermedium)
Two introduced grasses, intermediate and tall wheatgrass, dominated roadsides and dry canal banks. They tolerate alkalinity but aren't wetland grasses (so I didn't pay as much attention to them).
That's all for now. Thanks for joining me on this adventure to the Summer Lake Refuge.
A big thank you to my adventure photographer, who captured the special moments for us.