Saltgrass

Distichlis spicata

Overview

Overview

Saltgrass (Distichlis spicata) is a widespread grass native to the Americas but naturalized on other continents. It is most common in areas of moist saline or alkaline soils, and is a major component of the vegetation in the lower parts of San Elijo Ecological Reserve.

Like other salt marsh species, saltgrass can grow and reproduce at salinities that would kill most other plants. The surface of each leaf is equipped with many tiny salt glands that remove excess salt from plant tissues by excreting drops of highly concentrated saltwater onto the leaf surface where it will be washed off by high tide, rain or fog.   Run a leaf between your fingers; the gritty feeling is caused by  tiny flakes and crystals of dried salt. Look closely at a leaf in the sun; the crystals sparkle like tiny diamonds.

                        

Description

Description 2,4,11,67,129

Saltgrass is a spreading perennial grass from horizontal stems (rhizomes and stolons) that produce roots and new plants along their length, much like Bermuda grass; one plant can give rise to a dense stand. Saltgrass is generally low growing, less than 20 inches (50 cm) in height. Leaves  (blades) are produced alternately from the joints (nodes) of upright stems; leaves of each side lie in a single plane, giving the plant a pressed look. Leaves are four inches (10 cm) or less in length, narrow, linear narrowing to the tip, rolling inward along their length. The leaf base is a membranous sheath that wraps around the stem. Leaves lack hairs. Salt glands on both surfaces excrete drops of saline water that initially resemble heavy dew and evaporate to salt flakes and crystals that give the leaves a gritty feel and sparkly appearance.
 
Saltgrass flowers(florets) are not common. In the Reserve, we have only observed a few plants with flowers or seeds, and these were all nursery-raised plants recently transplanted into a revegitation area. Unlike most grasses, florets are usually unisexual
(although exceptions have been reported 4,129); male and female florets occur on separate plants.  Florets are compressed front to back and up to 30 florets are tightly packed into spikelets which, in turn, are arranged into terminal inflorescences. Male flowers have three stamens with thread-like filaments. Anthers have two pollen sacs attached along the sides, giving each anther an "X" shape. Female flowers have a single, superior ovary with two styles with shaggy, pinkish stigmas.

Seeds are uncommon.4 Seed heads are dense and yellowish. The single seed is brown, smooth, ovoid, less than 1/16 inch (2.2 mm) long. It is initially dispersed with one floret bract (the palea) fused to the base.

         

  

Other Common Names: 
salt grass, inland saltgrass, desert saltgrass, seaside saltgrass, spike grass, alkali grass

Distribution

Distribution

Saltgrass is widespread, native throughout the United States, southern Canada, northern Mexico and areas of South America;89,67 it is naturalized elsewhere.41 In the western US it is found in wet alkaline areas inland as well as along the coast; elsewhere it is primarily confined to the coastal belt.89 It is listed as a native weed in Nebraska but is protected in Pennsylvania.67

Saltgrass is distributed throughout California below about 2400 meters.7 It is most closely associated with saline and alkaline soils,67 but has been reported from a variety of other habitats.7

In the Reserve, saltgrass is ubiquitous along the lower trails in all basins.

 

This plant occurs primarily in the following vegetation types in the San Elijo Lagoon Ecological Reserve: 
Coastal sage scrub
Coastal strand
Salt marsh
Salt Pan
Alkali Marsh

Classification

Classification 2,11,44,129

Saltgrass is an herbaceous perennial monocot in the grass family (Poaceae, formerly Gramineae). The grass family is the fifth largest plant family and is considered to be the most economically important, containing such important food crops as wheat, rice, oats  corn and sugar cane. Grass leaves elongate from the leaf base rather than the tip and this allows grasses to be repeated grazed without damaging the plant, making them excellent forage crops.41,310

Grasses have a unique terminology. They are recognized by their cylindrical stems (culms), which are generally hollow or pith-filled with solid joints (nodes). Leaves(blades) are flat, attached to alternate nodes; leaf bases wrap the stem forming the leaf sheaths.

Grass are most likely to be mistaken for sedges (Cuperaceae) or rushes (Juncaceae); This old jingle may help:
310


             "Sedges have edges
              and rushes are round.
              Grasses have nodes
              where the leaves are found."
             
           
Grasses are wind pollinated, and this has resulted in a highly modified flower structure with a unique terminology. There are no petals or sepals. The pistil and stamens are enclosed in two specialized bracts (the palea and the lemma); together these make up a grass floret. One or more floret is grouped along an axis (rachilla) forming a spikelet; beneath each spikelet are two additional bracts (glumes). Spikelets may themselves be clustered into larger assemblages. There are generally three stamens with long filaments and large anthers. The wind-born pollen is tiny. The pistil consists of a superior ovary and two plumose styles.

There are two species of Distichlis native to the United States (D. spicata and D. littoralis
129); both grow in the Reserve. They are distinguished from one another  by the vegetative growth form, by the number of spikelets in a cluster and by the number of bracts (glumes) at the base of a spikelet.2

           

Alternate scientific name(s): 
Distichlis stricta

Ecology

Ecology

Although 76% of the earth is covered by sea water, less than 2% of plant species are able to grow and reproduce where seawater is the primary source of water.41 Plants that survive in estuarine environments, including saltgrass, are among those special few. Most plants have some ability to prevent the uptake of toxic salts at their roots. This adaptation is well developed in estuarine plants. Nevertheless, exclusion alone is not sufficient and at least one other mechanism is necessary.

Saltgrass has developed tiny salt glands that occur in rows along both sides of the leaf blades. In saltgrass, these glands consist of two cells, a basal cell and a hemispherical cap cell. The basal cell is surrounded by "collector cells" which contain large vacuoles. It is thought that the excess salt is transported into the collector cells and then moved by the basal cell into the cap cell and ultimately onto the leaf surface. This movement appears to be powered by expansion and contraction of paired membranes which form channels through the basal cell, a bit like the action of tiny bellows.311

The excreted salt can often be seen with the naked eye appearing as drops of liquid or as tiny crystals or flakes of salt. The salt can easily be tasted.

The high concentration of salt may help guard against herbivory.34 In spite of the salt, however, saltgrass is the host plant for the wandering skipper butterfly (Panoquina errans), which is one of a small group of butterflies that have a unique was of holding their wings when at rest (sometimes called folded-wing skippers). The wandering skipper is on the IUCN list of threatened species,172 primarily due to habitat loss.34 The wandering skipper has been found in the Reserve.313

              

  

Human Uses

Human Uses 15,75

Indian tribes in California's Kern Valley collected saltgrass for its salt. During hot, dry weather, the grass was harvested and spread on mats just until the salt had crystallized, but the grass was still flexible; it was then pounded with poles to release the salt. Alternatively, in the early morning while still damp, the growing grass was swept with switches and the damp salt scraped from the switches and formed into balls or cakes. Yokuts from the San Juaquin Valley used similar techniques. Salt was an important trade item and was used sparingly.

Saltgrass appears to have been less important to our local Indians; presumably they obtained plenty of salt from the ocean. The Kumeyaay boiled the saltgrass and used the tea as a mouthwash "when the mouth was sore."16

In recent years, saltgrass has been used in the restoration of saline and alkaline wetlands where the strong root systems protect against erosion and buffer the adjacent land from pollutants carried by run off water.67 It is being grown in the SELC nursery for use in revegetation projects in the Reserve.

       

Interesting Facts

Interesting Facts 41,312

Salt is much more than a flavoring for hamburger and popcorn. It has played a vital role in the development of civilization around the world. Not only is salt a necessary component of human diet, but it is one of the earliest and most successful food preservatives. Many cities developed around inland salt deposits (Salzburg was named for its salt mines), and the salt trade stimulated the development of transportation corridors. Our word "salad" derives from the early practice of putting salt on leafy greens. Salt was so valuable that in some regions it was substituted for money. The Romans sometimes paid their legions in salt, ultimately giving rise to the word "salary" and phrases such as "worth his salt".

             

Photos

Aug. 2007
Central Basin, Nature Center; Oct. 2011
East Basin, dike; July 2009
saltgrass with alkali heath and salty susan; East Basin, dike; July 2009
Central Basin, south side (Rios trailhead); June 2009
Central Basin, south side (Rios trailhead); Aug. 2014
Aug. 2007
saltgrass with recently excreted drops of brine; Central Basin, south side (Rios trailhead); Aug. 2014
saltgrass with recently excreted drops of brine; Central Basin, south side (Rios trailhead); Aug. 2014
salt-covered saltgrass; Oct 2009; photo courtesy of Barbara Wallach
blades with salt flakes and crystals; Central Basin, south side (Rios trailhead); June 2009
flowering spike; East Basin, east side (Stonebridge Mesa); March 2015
male spike, with anthers exposed; East Basin, east side (Stonebridge Mesa); March 2015
spikes of developing seeds; East Basin, east side (Stonebridge Mesa); June 2016
ripening seed cluster; upper line points to a floret, the lower lines delineate a spikelet; East Basin, south side (Santa Carina trailhead); May 2016
nodes; blades clasping stems with membranous sheaths; Central Basin, south side (Rios trailhead); Nov. 2016
blade with salt crystals; East Basin, south side (Santa Helena trailhead); Nov. 2016
pots of saltgrass ready for planting; SELC greenhouse; Nov. 2016