Summer showers bring fall flowers

Bighorn Mountain Wilderness near Ruby Canyon

Spring time is the season when I usually get reacquainted with all my old flowering friends, go on wildflower walks, and spend lots of time doing what I love best; looking for plants! Who would have thought that late summer and fall could be just as amazing and floriferous as the spring season? There are currently billowing fields of flowers in California’s desert that resulted from several significant storms this past summer in August and September. This year I have been able to take several field trips to view the spectacle of desert flowers at a site called the Bighorn Mountain Wilderness.

The Bighorn Mountain Wilderness is the subject of an ongoing RSABG research project to inventory and create a checklist of all the plants that occur in the area with special attention to documenting rare and invasive plants. The Wilderness is 38,502 acres and set back against the north side the San Bernardino Mountains in San Bernardino County, California. Our partners on this project are the Bureau of Land Management and the San Bernardino National Forest who both manage portions of the wilderness.

Fields of brightly covered chinchweed blanket the floor

Last week on 26 September 2013, 12 staff and students from RSABG set out to document the spectacular fall bloom.The area is difficult to access without a four-wheel drive vehicle; therefore few botanists have documented plants in the Wilderness prior to our study. After traveling one hour via dirt road and one flat tire, we got to our survey sites and found an abundance of summer annuals. We also found perennials that normally bloom in the spring, but have perked up in response to the summer rain.  

The summer annuals that predominate and form carpets in the Bighorn Mountain Wilderness are: fringed amaranth (Amaranthus fimbriatus), needle grama (Bouteloua aristidoides), six weeks grama (Bouteloua barbata), Sonoran sandmat (Euphorbia micromeria), Yuma sandmat (Euphorbia setiloba), and chinchweed (Pectis papposa).

Other less common annuals include windmills (Allionia incarnata) and spinderling (Boerhavia triquetra var. intermedia).  Shrubs in the sunflower family such as wedgelead goldenbush (Ericamerica cuneata), rubber rabbitbrush (Ericameria nauseosa), round-leaf rabbitbrush (Ericameria teritifolia), and scale broom (Lepidospartum squamatum) are approaching full flower and create a haze of yellow across the landscape.

Mirabilis (four o'clock) in bloom in September 2013

If you have a chance to get out and see this spectacular bloom I would hightly recommend it.  Swaths of blooming plants can be seen just outside of the Bighorn Mountain Wilderness, north of Yucca Valley near the town of Landers. There in Johnson Valley you will find fields of chinchweed and spiny senna (Senna armata). There are also several other locations to see the unusual green cast in desert.  If you head out along I-10 towards Desert Center you will find octotillo (Fouquieria splendens), pallo verde (Parkinsonia florida), and ironwood (Olneya tesota) lush and green with some plants in flower and fields of gramma grass (Bouteloua sp.). 

Stay tuned to our website for updates on our progress and findings in the Bighorn Mountain Wilderness and visit our photo album to see more.  The area is an interesting transition zone between the Mojave and Sonoran deserts and the interior mountains of southern California. Over the course of our study we are sure to have many interesting discoveries that will enhance our knowledge of California’s diverse flora.