California – a study in diversity
By Fiona Dennis
I departed for California in June 1994, on a six week journey that was to both enrich my knowledge of America’s native flora and to broaden my horizons in horticulture. It was also to prove challenging in a number of other ways too!
My first stop was Los Angeles, City of Angels, where I managed to find the seediest of hostels which afforded me a mattress on the floor. The next morning I discovered there had been a triple killing in the next block down and a number of enlightening facts about this area were revealed in details not for the squeamish. I determined to hire a car that day and head for the State Park in Malibu.
Learning to drive an automatic car on the right hand side of an eight-lane freeway in central L.A. brought its own rewards. It was with great pleasure that I pitched my first tent of the trip, noting the ever present danger of catching Lyme Disease, picked up by walking in tick-infested grassland. The Malibu Creek State Park was my first observation of chaparral, an ecological niche so characteristic of this region. Typical plant species include Artemesia rothrockii, Penstemon sp. and Argemone. There is also riparian woodland, containing Quercus agrifolia and Salix sp. as well as the rocky foothills which support, among other species, the rare Dudleya transkiae. Malibu Creek State Park is of national significance as it encompasses one of the last remaining fragments of primary Valley Oak woodland (Quercus lobata).
Then I attended a conference, ‘Common Ground’, in Pasadena. This was arranged by the American Association of Botanic Gardens and Arboretums and hosted at the Huntingdon Botanic Gardens. This is a superb botanic garden with a large cacti and succulent collection (outside, of course). These include specimens of Fouqueria splendens, Opuntia sp. and Euphorbia sp. of massive dimensions. There is also an authentically designed Japanese Garden with a Zen bamboo garden, a moon bridge and a traditional, raked, gravel garden. The conference consisted of a number of lectures and workshops. Emphasis was on the conservation of native species both in-situ and ex-situ. Other topics included the role of botanic gardens in relation to the local people. Discussion focused on how a botanic garden could meet the needs of the local community as well as the botanical community.
My next destination was the Mojave Desert. This was as far south as I was to travel and at 126 C it was to be one of the briefest of my visits! However fantastic the cacti collection at the Huntingdon Botanic Garden was, it had not prepared me for the experience of an entirely xerophytic environment. The range of Opuntia sp., including the Jumping Cholla Cactus, (Opuntia biglovii), and Mamallaria sp., defied my humble efforts to record all that I saw. The wildlife was unexpectedly rich. During the daytime I saw Roadrunners and Jack Rabbits galore. Snakes were not uncommon and I was lucky to observe a three foot long Rattle Snake stretched across my path (it would have been very unlucky if I hadn’t!). At dusk the Tarantula spiders come out and at night the Desert Mouse, the bats and the night owls inhabit the environment. I drove through the Josua Tree State Monument and observed the tree-like Yuccas (Yucca brevifolifolia), stretching out their branches, looking like Josua pointing to the west – according to the pioneer Mormons. Momentarily, and much to my amazement, it began to rain. Here in the desert, I experienced the only rain of the trip.
On the drive from the south I passed through much Sagebrush country and spent some time counting species variety and density of the native species growing in this dry and frequently burnt, environment.
The next area I visited was Mono Lake. This is a saline freshwater lake that is replenished annually by the snow-melt from the High Sierras. It has a unique ecological system because of its high salinity. Migrating birds flock here to feed on the Brine-Fly that breed in this brackish water. It is one of the only breeding sites for the Californian Seagull and it is a vital refuge for a number of rare breeds of other birds that depend on the site for rest and food. This beautiful, blue lake has tall, statuesque pillars of carbonated limestone protruding from the surface. These indicate the falling level of the lake. This has resulted from the siphoning-off of the water to supply the city of LA and the irrigated agricultural lands of the San Jonquin Valley. The arguments of ‘Man versus Nature’ continue and this was to be only one of the many debates about water and its utilisation that I was to come across during my travels.
I then camped in the Yosemite National Park, in the shade of the mighty pines found in this region. The primary health hazards here, (to my health), were Bear and Cougar – small fry after the Rattle Snake. I was lucky to catch the end of the flowering season in Tuolomne Meadows. There were plenty of Dodecatheon sp., Cammasia lietchlinii and Polygonum bistortioides to be seen. In the woodland and riparian paris of the park there were many specimens of Aquilegia formosa, Delphiniumconsolida, Rein Orchid (Harbenaria sp.), Lilium sp. and the heavily scented Azaleaoccidentalis. It was whilst looking for the source of the Yosemite hanging waterfall that I experienced my next close shave with death: in the true tradition of plant hunters, I was reaching over a white-water rock pool to take a photograph, only to find myself tumbling, concussed, under water. Myself and my camera, though both dented, survived.
The conifers of California are varied and extraordinary. The Bristlecone Pines, Pinus aristata, of the White Mountains are over 4,000 years old, whilst the Sugar Pine, Pinus lambertiana, has cones of up to 26″ long. This is only matched by Pinus coulteri, which has the world’s heaviest pinecone. The small Pinyon Pine, Pinus monophylla, has interest as a food source for the native peoples, who would travel considerable distances to harvest their pine kernels.
At the northern extreme of my trip I climbed Lassen Peak, 3,187 m, and observed those plants that had managed to evolve survival strategies for such a punishing climate. (This is also an area that has a problem with plague-infested Chipmunks, curiously enough). I also walked in the fog-enshrouded forests of the mighty Coastal Redwoods, Sequoia sempervirens, and visited the Pacific Lumber Company (well known for its particular interest in these trees). I also found the Banana Slug, a striking invertebrate of about 8″ long and bright yellow.
I took the coast road back south and camped in Point Lobos Reserve. Here I saw the remaining two stands of the Monteray Cypress, Cupressus, clinging precariously onto the cliff faces.
Throughout this journey I was welcomed and guided around botanic gardens. I visited Rancho Santa Ana in the southern part of the State, where I was kindly shown around by the Curator, Dr. O. Mistretta and Bart O’Brien. Here they grow exclusively the flora of the State and their efforts to protect, preserve and develop protocols for cultivation of rare and threatened plants shows the greatest commitment. I also visited Tilden Botanic Garden, part of the East Bay Regional Parks. Stephen Edwards, the Curator, kindly spent a few hours showing me around and explaining the finer taxonomic issues raised by the latest publication of ‘The Flora of California’ by Muntz -the definitive book on Californian flora. Also Berkley Botanic Gardens, where Roger Raiche, Curator and Holly Forbes, Deputy Curator, spent much of their time showing me around their Garden. At Santa Barbara Botanic Garden, I met Betsy Collins, the Living Collections Manager and Dieter Wilkens, the Director of Research. They introduced me to their extensive native plant collections, including a serpentine bed, an ecological niche often overlooked for its botanical interest.
The trip has been a great enlightenment to me. I have not only observed the native plants of California and the protocols for their cultivation, but also been able to appreciate the efforts being made to protect them, both in-situ and ex-situ. In addition I have discovered the geological diversity of the State and its evolutionary effect upon the great many endemic species unique to California. Above all, perhaps, I have learnt about the ecological diversity of the State, its significance to the flora and fauna and its vulnerability to change, both natural and manmade. Much of what I have learnt was unforeseen in my original objectives: many of the issues facing the conservationists in California, for example; the naturally occurring problems caused by fire and drought and those caused by man; land development and irrigation. I also discovered something of the history of the plants themselves, through documentation about the native peoples of the State and their sustainable use of plant products.
I would like to extend my sincerest gratitude to the Kew Guild without whose kindness and generous support I could not have undertaken the trip and have benefited in so many different ways.