Slender Glasswort

Salicornia depressa

Slender glasswort (Salicornia depressa) is one of three pickleweeds reported from San Elijo Lagoon. It is small annual plant that grows around the salt flats in East Basin. In mid-summer, slender glasswort turns deep red and paints colorful swirls over the otherwise barren ground.

In the 18th century, ash from incinerated glasswort was used in the manufacture of soda glass, prized for its crystal clear color. This gave this pickleweed its common name.

Like other pickleweeds, slender glasswort is considered a delicacy, eaten raw or cooked.

Other Common Names:

Virginia glasswort, American glasswort, common glasswort, annual pickleweed

Description 2,306,413

Slender glasswort is a low-growing, succulent annual herb, related to and resembling other pickleweeds. The main stems are vertical, up to 2½ feet (70cm) in height; many of our mature plants are less than 6 inches (20 cm). Stems appear jointed. Joints of the flowering stems are cylindrical to barrel-shaped. In the summer, the entire plant turns rose-red to purple or bronze.

The leaf base closely sheaths the stem, from which it isre indistinguishable. The blade is reduced to a collar-like scale surrounding the stem. The top leaf blade is reduced to a small hyaline band with an obtuse to widely acute upper edge.

Flowers are greenish-white, tiny and inconspicuous, arising from and largely concealed in the tissues between stem segments. At each junction, there are two clusters of three flowers each. The three flowers are arranged in a triangle with two, smaller flowers touching below the central flower. Each flower has one or two stamens (we have only observed one in our material) and a pistil with two plumose stigmas. Flowers are wind pollinated. Flowers are usually reported between July and September, but ours often bloom earlier.


Slender glasswort is reported along both coasts of North America in salt marshes and alkaline flats mostly along the coast below 500 feet (150 m)89, but occasionally in mountain dry lakes.7 Along the Pacific, the latitudinal distribution extends from Alaska and Canada  into Baja California.

In the Reserve, in some years, slender glasswort forms sizeable populations along the edges of our remnant salt flats. These are low areas that typically flood during the winter forming shallow ponds.411 Evaporation during the rest of the year deposits salts dissolved in the water, often leaving a visible crust of salt. Either the high salt concentration or the prolonged periods of winter flooding (or both) prohibit extensive vegetation growth. When flooded, salt flats provide feeding grounds for water birds. Historically, as the ponds dried in the summer, they were used as nesting areas for least terns and snowy plovers. Before the arrival of Europeans, salt flats were a conspicuous feature of the six lagoons in northern San Diego County, but most of the salt flats have been reduced or altered by subsequent activities within and around the marshes.411

Two places to see slender glasswort are the summer-dry areas east of the old dike and east of the access road between Santa Helena and Stonebridge Mesa. In the summer, the plants turn a deep reddish, forming colorful displays. Other slender glassworts may be scattered throughout the marsh, but because of their small size they would be easy to overlook.


Slender glasswort is a dicot angiosperm in the goosefoot family, Chenopodiaceae.2 Plants in this family are often succulent or scaley; many appear weedy; many are salt tolerant. Typical flowers are tiny, greenish and lack petals.11,34,44,310 The goosefoot family includes well-known edible species such as chard, beets and spinach, as well as the invasive tumbleweed (Salsola tragus), accidentally introduced as a contaminant in flax seed about 1870.41

Glasswort is  one common name for several similar species of low-growing succulent salt-tolerant plants, often called pickleweed.. There are two other species of “pickleweed” reported from the Reserve: common pickleweedS. pacifica, and a somewhat shrubbier species,  Parish’s glasswort, Arthrocnemum subterminalis.48  Slender glasswort is distinguished by its smaller size, annual life cycle, early fall color and by the triangular arrangement of the tiny flowers.

A recent phylogenetic study and partial revision of the genus was given the pithy title “A Taxonomic Nightmare Comes True”.413Slender glasswort was previously considered part of a world-wide species, S. europeae. In the recent treatment, the annual species in North America were separated from the European species, and S. depressa was given the name of a common and widespread species in coastal areas.  There is some reason to think that the S. depressa of North America is still a complex of species that needs further study. Specifically, the Atlantic population seems “quite distinct” from that along the Pacific.306 This may explain some apparently contradictory descriptions found in the present literature.


Like other pickleweeds, slender glasswort has special adaptations that allow it to use seawater as a primary source of water.31,174However, the apparent association of slender glasswort with salt flats suggests it must also tolerate prolonged seasonal flooding. It has been suggested that the evolution of the annual life style among some pickleweeds is an adaptation to seasonally harsh environments – subarctic environments to the north and salt flats in the south. The untested assumption is that annual pickleweeds persist as seeds during cold or inundated periods, germinating when conditions improve.413

Human Uses

The various species of glasswort and pickleweed appear to have been used interchangeably by our local Native Americans. Kumeyaay chewed the raw stalks for salt.16 The Chumash used the stems as a seasoning and a vegetable and used the ashes to make soap.403

In the 18th century, pickleweed was a source of soda ash for early glass making, which is why species in this genus are sometimes called “glasswort”.41

Today, the pickleweeds may be best known as vegetables, “a crunchy, briny delight”.412 Stalks are called “sea beans”, “sea asparagus” or “sampire” and are eaten raw as a garnish, pickled or cooked as a vegetable.28,29,412

Interesting Facts

The association of slender glasswort with the salt marsh and remnant salt flats is reflected in the generic name, Salicornia that comes from the Greek roots “sal” for salt and “cornus” for horn; together they indicate a salt-loving plant with horn-like branches.21

“Sal” is also the root of the word salary, reflecting the importance of salt for civilization.41,312 For coastal Native Americans, salt was an important trading item.15,411  Many European cities developed around inland salt deposits (Salzburg was named for its salt mines), and the salt trade stimulated the development of transportation corridors. Salt was so valuable that wages were sometimes paid in salt, hence the word “salary.”41,312

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