The approaching cold season means colorful flowers no longer adorn our landscape, but there are still many plants evident at this time of year that are worthy of our attention. This month we’ll look at what is probably the most abundant and significant shrub on the Preserve, four-wing saltbush. The name refers to the distinctively winged fruits and the plant’s ability to thrive on salty soil. Perhaps the most common shrub west of the Mississippi, it is understandable that four-wing saltbush is known by several other common names including saltsage, four-wing shadscale, bushy atriplex, white greasewood, as well as the Spanish name chamiso (and its derivatives chamise and chamize). Its scientific name, Atriplex canescens, comes from first, the Greek name for orache (atraphaxis), an edible weed; and second, the descriptor canescent meaning “turning hoary white.”
Four-wing saltbush is a thickly-branched, long-lived perennial that grows up to five feet tall. Its main stems are whitish in color, woody, and may become quite substantial in diameter. The root system is deep, accounting for the plant’s drought tolerance and significant value for erosion control. The gray appearance of four-wing saltbush is primarily a result of fine whitish hairs that cover the leaf surfaces. Rather small, elongated leaves are distributed along the branches in an alternate, often somewhat sparse pattern. In salty conditions the plants take up and accumulate salt from the soil, secreting excess salt as crusty deposits on the leaf surfaces.
Four-wing male flowers
The yellowish flowers of four-wing saltbush are rather inconspicuous and appear in the summer. Male and female flowers are produced on separate plants; botanists call such plants dioecious. Clusters of pollen-bearing male flowers are produced along the tips of the branches of male plants (left photo above). Female plants produce clusters of even tinier flowers from the tips of branches to points farther down along the branches, consequently many female flowers occur at the base of leaves (right photo above). After successful wind pollination, each female flower will develop a single seed within a fruit structure that forms four thin, flat outgrowths. These dry fruits tend to persist on the stems throughout the winter (right photo below). The presence of these distinctive four-winged seed pods makes it easy to distinguish female from male plants as in the left photo below of two plants growing side-by-side along Jumano Trail, in this case the male is the plant on the left.
Four-wing male & female bushes
Four-wing fruits
Four-wing saltbush is a member of the goosefoot family (Chenopodiaceae), plants with small flowers generally growing in disturbed, saline, and/or dry habitats and therefore the family is well-represented in New Mexico (19 genera and 71 species). Several food crops including spinach, beets, chard, sugar beets, and quinoa are members of the goosefoot family. The locally-abundant introduced noxious weeds lambsquarters, Russian thistle (tumbleweed), and kochia are also members of this family. Four-wing saltbush is a particularly valuable wildlife plant in our area providing nutritious winter forage for deer, antelope and elk (as well as cattle) and cover for numerous birds, rabbits, and various small mammals.
Such a widespread and abundant plant might be expected to have many traditional human uses and indeed Native Americans found uses for virtually all parts of the four-wing saltbush plant. Fresh roots were boiled to produce a drink for stomach pain or use as a laxative and dried ground roots were applied to toothaches. Leaves contain saponins and produce a soapy lather used to relieve itches and rashes. Dried leaves were ground and added to flour mixes. Crushed flowers were used in soap making and to produce a poultice applied to ant bites. Seeds are edible and were ground for use a baking powder or cooked in cereal. Even the ashes from four-wing saltbush were used in breadmaking recipes, as a food coloring, and in the production of lye. Clearly a plant does not need to have pretty flowers to be worthy of our respect and admiration.
A Botanical View – Dioecious or Deciduous?
These two completely unrelated terms have caused untold confusion among generations of botany students. Since the term dioecious was introduced in the above essay, I will attempt to head off any potential misunderstanding. Many people are familiar with the term deciduous, which is defined as “describing woody perennial plants that shed their leaves before the winter or dry season.” The opposite of a deciduous plant is an evergreen plant.
Fewer people are familiar with the term dioecious, which has nothing to do with leaves or seasonality. The term dioecious is defined as “describing plants in which the female and male reproductive organs are separated on different individuals.” The opposite of dioecious is monoecious which is defined as “describing plants in which the female and male reproductive organs are separated in different floral structures on the same plant.” The majority of flowering plants are neither dioecious nor monoecious because their flowers are bisexual, having both female and male reproductive organs in the same flower.
Therefore the terms monoecious and dioecious apply only to those plants with separate male and female flowers. An example of a monoecious plant that most people are familiar with is corn. The pollen-producing male flowers are located in the tassel at the top of the plant. The female flowers are usually not visible because they occur in clusters at the base of a large corn leaf, each one producing a single silk that extends away from the leaf to catch pollen grains. An example of a dioecious plant is four-wing saltbush. Incidentally four-wing saltbush is also a deciduous plant, but it does not necessarily shed all its leaves each winter. I have seen the term semi-deciduous used in such cases (the natural world is not black and white).
© 2008 Jerry Melaragno