Study tour to the Southwestern United States
By Patrick Garton
The duration and time of year of one’s travels can significantly determine what regions of the globe are most suitable for botanical exploration. I was able to get three weeks together which had to be taken in March. This meant it was now worth spending more on a longer haul flight, while going at this time of year was ideal for visiting a corner of the world that had always fascinated me: vibrant colours of spring flowers against clear blue skies standing out from the mysterious ochre landscape of North America’s Southwest.
On the 1st March 1998 I arrived in Phoenix, Arizona. My first memories were of driving through the city that first morning fuelled with an amazement that comes while travelling through that legendary landscape of giant saguaro cacti (Carnegiea gigantea) which, together with yuccas, barrel cacti (Ferocactus spp.) and the yellow blooming paloverdes (Cercidium spp.), are used extensively in roadside landscaping across the Southwest. And as if this didn’t seem staged enough, roadrunners and howling coyotes were to come that evening!
The visitor’s first experience of that classic `wild west’ scenery can be felt at Phoenix’s Desert Botanical Garden with a superb interpretative trail showing and explaining the features of Sonoran Desert plant life. This is about the northern-most limit of the low desert. Heading south and east to Tucson the higher ground and increased summer rains coming from the Gulf of Mexico produces saguaros at their densest. The Arizona-Sonora Desert Museum in the middle of the Saguaro National Monument (under `Park’ jurisdiction) is another must, introducing the visitor to the ecology, geology and natural history of this part of the desert. Sunsets from the museum’s balcony are out of this world: a hazy expanse stretches out before you, broken by the sharp silhouettes of columnar cacti and all hemmed in by distant mountain ranges.
Beckoned by the reputation of spectacular spring flowers further west, I then trekked towards California, passing by the Organ Pipe Cactus National Monument. No matter how hard anybody tries to describe the endless carpet of wild flowers, the reality is still harder to believe. Here the completely unspoilt landscape is ablaze with penstemons, owl’s clover (Orthocarpus purpurascens), Californian poppies (Eschscholtzia californica) and Fiddlenecks (Amsinckia intermedia). Towering above these are the familiar humorous forms of saguaros and organ pipe cacti (the only locality they can be seen in the U.S.A., since this lies on the Mexican border). This was not all! Further west into California lies the Anza-Borrego Desert State Park. This marks the furthest point west before reaching the 3,000 plus metre high Coastal Ranges separating it from San Diego. Getting almost all its annual rainfal in the winter, this side of the Sonora Desert is probably the richest in spring flowering species. Under leaden skies, pierced sporadically by intense shafts of sunlight, the scenery appeared almost lunar. Sparsely but uniformly dotted between creosote bushes (Larrea tridentata) were new acquaintances: monocultural stands of sand verbena (Abronia villosa) and dune primroses (Oenothera deltoides).
Having come so far, two final sites had to be visited. The Joshua Tree and Death Valley National Parks still had their turn to impress with their unusual subjects. Climbing all of a sudden from low to high desert it became apparent that the Mojave Desert was very different from anything I’d experienced up till now. Slowly, from groups of different low growing yuccas (Yucca schidigera and brevifolia, the Joshua Tree) I noticed one of these species attaining ever increasing proportions until at the top it now reached heights of 10 to 15 metres. Surrounded by a biting clear air, some of these grotesque figures had survived 200 years. Early Mormon settlers had called it the Joshua tree because the plants seem to lift their arms in supplication like the biblical Joshua.
I then descended into Death Valley after crossing the Mojave Desert. Boldly disguising a reputation for the highest temperatures recorded in the U.S.A. and belying its title and place names within the Park such as Furnace Creek and Devil’s Golf Course, the valley welcomed visitors at this time of year with an abundance of life and colour. In fact the Park authorities proclaimed this the best in 20 years for its displays of spring flowers.
An excellent Park system is provided by the National Park Service in the U.S.A. With trails and daily activities such as talks and video programmes at visitor centres and comprehensive bookshops and campsites within parks, these added to the memories and knowledge I gained from each site, making the southwestern U.S.A. one of the most enjoyable destinations that can be visited at this time of year.