Slender Glasswort

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.

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.

Classification  

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 pickleweed, S. 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”.⁴¹³ Slender 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.

Ecology  

Like other pickleweeds, slender glasswort has special adaptations that allow it to use seawater as a primary source of water.^31,174 However, 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