Native Plants of the Southwest (48) - Palm Canyon, KOFA NWR, AZ
Whether you prefer a short day hike on a maintained trail (Palm Canyon), a long day hike on a primitive trail to the summit of a lofty desert peak (Signal Peak), or a scramble on class three rock (Castle Dome), you can have it all on the KOFA NWR. Pick your poison. I'll focus on the short hike to Palm Canyon here. The others are nearby, so you can explore further as you wish.
The plants I discuss below are not restricted to any particular site, with the exception of the palms. For them, you'll need to hike in Palm Canyon. Broom Snakeweed is a small shrub in the Sunflower Family. It is quite widespread, so it's a good one to know as you will run into it eventually on any desert hike in the Southwest. Nightblooming Cereus is a cactus that is often overlooked, as it knows how to hide its spindly stems among desert shrubs like Creosote. Finally, Rattlebox Senna, is a member of the Pea Family that makes a characteristic rattling noise as you brush by it or if the wind is blowing just right. It is found far beyond the KOFA's, in such diverse places as the Grand Canyon, Saguaro National Park, Organ Pipe Cactus National Monument, and Agua Fria National Monument to name just a few.
Reaching KOFA NWR is straight forward. Take US Hwy. 95 south of I-10 (Quartzite) or north of I-8 (Yuma) to mile post marker 85. A good dirt road winds east 7.2 miles to a large parking lot and the trailhead. There are several informational displays at the trailhead explaining the occurrence of Arizona's only extant grove of native California Fan Palms. The trail is short, 1/2 mile to a sign pointing out the palms. The views are restricted to the west since towering cliffs lie immediately to the east. There are no facilities at the trailhead, not even a trash can. No water, no developed camp sites, nothing. No fees. Camping is not permitted at the trailhead. But there is lots to be enjoyed on this easy hike, like the clean air, vast views, and possibly some fine, like-minded companionship if you are hiking with family or friends.
Broom Snakeweed, Gutierrezia sarothrae (Sunflower Family)
Let's start off with a little survival tip: If you ever need to start a fire in the wilderness, this would be a great plant to use. It is loaded with flammable substances, so it is set aflame with just a little spark. It offers a picture of how volatile our words can be when we do not carefully consider how we speak to others as the Apostle James reminds us in the New Testament. Consequently, it becomes quite abundant on overgrazed land, since livestock won't touch it. Like most members of the Sunflower Family, its flowers are a bright yellow. It's a sub-shrub, so it doesn't get very tall, about 30 cm. It bears no thorns, spines, or prickles, so it welcomes your touch. Its leaves are small and shiny green, due to its chemical composition. Plants are given names, scientific and otherwise, to reflect specific characteristics. For example, other common names for this plant include: Turpentine Weed, Matchweed, Matchbrush, Resin-weed, Broom-weed, and Broombrush. The species name, or specific epithet is based on the Greek word sarum, for broom. So, this plant has been used as a broom or whisk. Additionally, it has been put to a variety of medicinal uses, such as to relieve sore muscles or to reduce the swelling associated with insect stings. Names like Matchweed have less to do with its flammable qualities and more to do with the appearance of the flower heads once the fruits begin to develop, after the ray flowers fall off. Thanks to Epple in Plants of Arizona and the authors of Plants of the Grand Canyon for sharing their insights on this toxic species.
Nightblooming Cereus, Peniocereus greggii (Cactus Family)
I have stumbled across this cactus only a handful of times, as I have probed into the branches of a variety of desert shrubs for one reason or another. The stems of this cactus blend in well with the stems on the shrubs. Since it blooms at night, it is even less likely to be seen in flower. About the best way to find one is when it is in fruit. It's large, red fruits persist for some days, contrasting nicely with the brown stems of its sheltering shrub. Native Americans historically used the flowers, fruits, and roots. The latter can become quite large, weighing up to 40 kilograms. Now, however, it is protected by the Convention for the International Trade of Endangered Species, according to Hodgson in Food Plants of the Sonoran Desert. In fact, the Gila River Pima reservation community prohibits its destruction or removal. This is the first native plant law of its kind enacted by a reservation community. It is sometimes found planted at homes on the reservation for its historic significance and the fragrance of its flowers. This fragrance can be detected many meters from the plant, attracting pollinators from some distance, especially when many flowers bloom simultaneously. In addition to providing food, Queen of the Night has been a source of medicine and contributes to controlling the onset of Diabetes II in Native Indian populations. As with any rare plant, its survival involves a complex suite of natural and human factors such as pollinators and pesticide use, grazing and land development. Once it's gone, it's gone forever and that's not what forever is for. It's here for a reason, let's hope the wise use of the land where it naturally occurs supports its survival rather than its demise.
Rattlebox Senna, Senna covesii (Pea Family)
Fruits are funny things. They have been put a variety of uses throughout history due to a marvelous suite of useful qualities and characteristics. For example, one website lists 27 household uses for citrus, such as: puree orange peels in one cup of warm water. Slowly pour the solution over and into anthills to get rid of them. (http://www.apartmenttherapy.com/27-household-uses-for-citrus-f-46057) Gourds have been used to make toy rattles as well as bird houses. Bean pods have been an important source of protein in the diets of people and livestock throughout the history of agriculture. Additionally, legumes improve the nutrient level of soils and provide a wide range of chemicals for cosmetics, pharmaceuticals, etc. Rattlebox may not have found commercial use, but the noise made by these bean pods is curious, fitting in well with the long history of funny fruit attributes characteristic of this family. The first thing I think of when I hear the pods rattle is a rattlesnake. But it's soon obvious that the sound is not from a snake. Looking around, this plant soon comes into view. The flowers are a dull yellow and the leaves a soft, grayish green with a divided blade. It grows upon dry hillsides or in gravelly washes at low elevations. The pods eventually split open and release their store of seeds, making them less noisy but not entirely so, as they still male a little noise as they brush against each other in the wind. The entire pod will finally fall off, making the desert a little quieter until the next crop of fruits appear in early summer. Traditionally, the Pea Family is divided into three sub-families: Mimosa, Caesalpinia, and Papilio. Senna is in the relatively small middle group along with such plants as Paloverde and Mexican Bird of Paradise. The Mimosa group has puffball-like flowers and the Papilio group's flowers resemble butterflies. The Caesalpinia group's flowers are midway in their appearance, larger than the Mimosas and more open than the Papilios. All in all, this is a lovely plant, at least to your eyes. It's a little odd when it comes to the sounds it makes, but that is just one more reason to appreciate hiking in the drier parts of the Southwest.
California Fan Palm, Washingtonia filifera (Palm Family)
Palms are tropical plants. Consequently, few naturally occur in the Southwest. The deserts of Arizona and California are at the northern distribution limit of native palms such as the California Fan Palm. Some palm species are more sensitive than others to cold, but in general, they do not thrive in places where winter temperatures dip below freezing. They also need plenty of water whereby their shallow roots can keep the tree alive. This is an unexpected need for a desert inhabitant. They have other needs too, some that people have played a significant role in maintaining. Fire has been an important management tool with a variety of vegetation types and palms are no exception. According to Gary Nabhan (Gathering the Desert) and Wendy Hodgson (Food Plants of the Sonoran Desert), Indians such as the Cahuilla periodically burned palm oasis to increase fruit yield by killing insects that ate the fruit. Such torched oases have troubled some environmental purists seeking to visit palms in their presumed natural state. However ugly they may look, periodic fires set by historic Indians killed back competing plants and debris. Water and nutrients were made more readily available to the palms, greatly increasing fruit production, and the associated reproductive potential of these stately trees. There are always winners and losers where humans have played a long-standing role in habitat modifications. Interestingly, in the case of palms, people did not act alone to make things better for palm trees, but partnered with the palms themselves to improve conditions for palm tree survival and reproduction. According to Nabhan, palms, once established, create soil conditions and a buffered microclimate that encourage future generations of palms. Things rare are things cherished. Therefore, since palms are rarely observed in the wilds of Arizona, visiting Palm Canyon might be at the top of your list of places to see this year, as it offers the easiest access to these useful and unusual native plants.