Sarcobataceae

Greasewood Family

Black Greasewood

FAMILY: Greasewood family (Sarcobataceae) – Sarcobatus genus. The Sarcobatus genus was formerly placed in the goosefoot family (Chenopodiaceae), and then the Amaranth family (Amaranthaceae), and then finally its own family.

SPECIES: Black greasewood (Sarcobatus vermiculatus (Hook.) Torr.).

TO UTILIZE AS FOOD: Warning! The young twigs and fleshy leaves are very high in oxalates (9-22% of the dry weight), primarily in the form of sodium oxalate. This concentration is one of the highest in desert shrubs. When consumed in moderation in combination with a balanced diet, oxalates are generally not a problem for healthy individuals. When consumed in excess, oxalates are very dangerous and capable of damaging renal tubes (tiny filtration units) in the kidneys. Oxalates occur in many forms, some of which are soluble and others that are insoluble. Soluble forms (such as oxalic acid, sodium oxalate, and potassium oxalate) are readily absorbed, but they can be removed by rinsing the plant material prior to consumption. Insoluble forms (primarily calcium oxalate) cannot be removed, but they are poorly absorbed. After ingestion, the human digestive system attempts to convert soluble forms into insoluble forms to be excreted. It’s very good at this task assuming the overall diet is healthy. Problems arise when excessive amounts of soluble forms, such as those in black greasewood, overwhelm the digestive system and enter the bloodstream. After some complicated biochemistry, they eventually form crystals that damage the kidneys. From a forager’s perspective, subsisting exclusively on oxalate-rich wild foods would be a serious mistake. Black greasewood leaves are responsible for numerous livestock fatalities, which occur when fresh leaves equaling 2-5% of an animal’s weight are consumed over a short period of time. For a 100 pound sheep, that’s approximately 2-5 pounds of fresh leaves. As little as 1 pound can produce symptoms of poisoning when unaccustomed sheep feed exclusively on black greasewood leaves. Oxalate poisoning is rare in humans because humans rarely consume enough plant material to cause poisoning. Nevertheless, oxalates are dangerous and should be approached with caution. Due to the high concentration of oxalates in black greasewood, only small amounts of the various parts should be eaten.

The young twigs and young leaves can be prepared as vegetables, and the seeds can be added to porridge. Other parts of black greasewood are inedible. Even the parts mentioned are barely edible due to the overabundance of unhealthful oxalates. Young leaves taste acrid, astringent, salty, and similar to spinach. The intensity of these flavors varies, usually ranging closer to palatable than unpalatable. Despite the oxalate content, the leaves aren’t very tangy. Leaf texture is tender, juicy, and succulent. Boiling improves the flavor by reducing astringency and tempering the mild burning sensation. Black greasewood forms colonies on barren alkaline lowlands inundated by seasonal rainfall. Young twigs appear in summer, followed by leaves and flowers. Seeds develop later in autumn. Young twigs are initially soft, but they soon become spiny. Male flowers may also have food value, but they are not reported to be edible. They first appear as green, cone-like structures about 1-2 cm long, eventually turning yellowish when the stamens release their pollen. Male flowers lack sweetness, but they taste better than the leaves. Female flowers are inconspicuous and unlikely to provide any food value. The seeds are also unlikely to provide any food value. Black greasewood seeds are packaged within winged structures that complicate the various processing techniques. These structures are tough and many of them are void of seeds, or the seeds fail to develop a starchy portion. Overall, black greasewood has minimal food value and should be regarded with extreme caution. Consumption is not advised.

NOTES: Judging by flavor, black greasewood really isn’t that bad. However, it’s not a shrub you want to eat in meal-size amounts. Vast stands of it cover the desolate Fish Lake Valley in western Nevada where I first tried the leaves. Notes on the flowers, twigs, and other parts came from Sego Canyon in eastern Utah and several other places. I was hoping the seeds would be a decent resource, but difficulties in processing them prevented me from acquiring a sample sufficient enough to merit documentation.

IDENTIFICATION: Currently, two species of the Sarcobatus genus are found in the United States, and identifying them is easy.

Description of black greasewood (Sarcobatus vermiculatus): FORM spiny shrub averaging 1-2 meters tall; LEAVES simple; alternate or clustered; sessile; blades linear to oblanceolate, thick, fleshy, and 1-4 cm long; margins smooth; surfaces usually hairless or occasionally sparsely hairy; FLOWERS unisexual, males and females separate but on the same shrubs (monoecious); MALE flowers in catkin-like spikes about 10-35 mm long; bracts peltate and shielding the 2-4 stamens; FEMALE flowers solitary or paired in the axils of leaf-like bracts; stigmas 2; FRUITS achenes small and prominently winged; generally cup-shaped below the wings and cone-shaped above the wings; SEEDS flat, round, about 2 mm in diameter, oriented vertically, and spirally coiled; seed coats membranous; HABITAT alkaline lowlands throughout the West, often forming pure stands around dry lakes; blooming April to September. NOTES: The other species, Sarcobatus baileyi Coville, endemic to western Nevada, differs by having shorter male flower clusters and shorter leaves that tend to be clustered on older branches.

REFERENCES: Black greasewood (Sarcobatus vermiculatus): young twigs Yanovski (p. 23); young leaves Couplan (p. 121) and Lahring (p. 150); seeds Couplan (p. 121), Lahring (p. 150), Moerman (p. 240), Rhode (pp. 51-53), and Yanovski (p. 23). References to oxalates: Burrows (pp. 356-357), Knight (pp. 263-268), Deshpande (pp. 353-354), and Turner (2009-b pp. 53-55).