Plant hobbyists and botanists from temperate regions have been known to refer to semi-arid landscapes as botanical deserts because for most of year everything looks dry and colored with shades of yellow and brown. If they were to visit these drier lands in spring, and look closely, they would realize that there is much diversity and color hiding in the nooks and crannies of the semi-arid desert areas.
Arid or Semi-Arid?
Webster’s definition of arid is: Excessively dry; having insufficient rainfall for agriculture; and lacking interest or life. Semi-arid is defined as having between 10 and 20 inches of rainfall a year.
Most of the rainfall in the semi-arid areas comes in the winter and spring. The plants that live in both arid and semi-arid climates have evolved through time adapting to survive in the harsh conditions.
During the winter, the hardy spring blooming natives of the semi-arid climates are dormant, yet busy absorbing all of the moisture they can get through their roots. When the soil warms in the spring they quickly begin growth, and are able to mature, bloom, produce seed, and once again go dormant before the extreme heat of the dry summer.
Soils in semi-arid landscapes tend to be dominated by sand, rock, gravel or clay. There is very little topsoil or organic matter present to nourish plant life. Due to deficient moisture, dead vegetation is very slow to decay, which is the reason for minimal organic layer and topsoil depth. The lack of organic matter also limits how well the soil collects and reserves the precious rainfall when it comes.
To mitigate the harsh conditions, spring blooming plants of the semi-arid desert each have a microclimate or niche location of preference. Some find shade and protection by situating themselves beneath shrubs like bitterbrush (Purshia tridentata) or sagebrush (Artemesia spp.), while others can be found growing out of cracks on north facing rock outcrops. The earliest bloomers are often found out in the open taking advantage of not having any competition from grasses that are still dormant.
Spring Flowers of the Semi-Arid Country
The earliest blooming native plants that show up in the spring tend to be more fragile and herbaceous. Yellow bells (Fritillaria pudica) are small, yet showy, yellow flowers that are often blooming before many other plants are growing, and before the desolate look of winter has totally dissipated. Buttercups (Ranunculus species) bloom shortly after the yellow bells. Neither species cause a riot of color or are present in blankets, but can be found scattered about adding modest bits of color.
Bitterroot (Lewisia rediviva) grows on rockier, more scabby areas of thin soiled basalt. Their flower colors range from white to bright pink with all shades in between. The flowers emerge from the fleshy roots shortly after the leaves. Once done blooming bitterroot is fairly inconspicuous because the fleshy leaves are linear in shape and not very long. Native Americans dug the roots and boiled them to eat, but that had to be done early before the roots turned bitter.
In spite of it’s homely name, dagger-pod (Phoenicaulis cheiranthoides) is an attractive and subtly colorful plant that also has a sweet, spicy fragrance. Dagger-pod grows from a woody root crown with many short branches that hug the ground. The leaves are gray-green and wooly which contrast nicely with the dense clusters of fragrant purple flowers. Much of the time when dagger-pod is blooming, mounds of blooming phlox can also seen, which make a nice display of the shades of white, pink, and lavender in the largely yellow and brown--with flecks of green--landscape.
The more showy and larger perennial flowers bloom a bit later in the semi-arid desert. The perennials tend to have deeper and more fleshy roots that can draw moisture deeper from the soil. They have more plant mass, so need more warmth, water, nutrients, and time to develop than the earlier blooming plants. One combination of perennials that is commonly found on the sagebrush steppe is arrow-leaf balsamroot (Balsamorhiza sagittata) and lupine (Lupinus species). In years of higher moisture, balsamroot and lupine can blanket an area in a sea of bright yellow and purple. It can be a truly stunning show!
Various species of Lomatium often bloom at the same time as balsamroot and lupine increasing color in the dry lands. Lomatium is a member of the wild carrot family and has blooms that range from a creamy white to bright yellow in color. The generic name for Lomatium species as a whole is wild parsley. Native Americans of the Great Basin and Columbia Plateau collected the stems of Lomatium nudicale in the early spring for food, which they call wild celery. It can be eaten raw and does have the distinct taste of garden-variety celery, yet is much more pungent and strong in taste.
The plants mentioned above are only a few of what can be expected to be found in the springtime in semi-arid climates. For those who are willing to take a close look at the nooks and crannies away from roads, many more intriguing plants can be found. However, it best be done in late April/May or you will miss them, and think you have landed in a botanical desert!
References:
Ronald J. Taylor, Sagebrush Country: A Wildflower Sanctuary, (Missoula MT, Mt. Press Publishing 1992).
USDA Plants Database. Accessed 1/30/2012.
Helen McGranahan - Helen McGranahan has worked her entire career dedicated to wise and sustainable management of natural resources.
