| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
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Horizons Backyard Botanical Boom Finding a completely new species requires a little luck, a lot of knowledge, and perfect timing. Given the pace of plant discoveries in California lately, there's no time like the present. Ask Jepson Herbarium botanist Dean Taylor. In May 1992, Taylor and fellow botanist Glenn Clifton stopped along Highway 299 in Shasta County to explore a limestone cliff that Taylor first noticed five years earlier. Fast-flowing Cedar Creek had kept Taylor from reaching the cliff before, but now that drought had dried up the stream, he and Clifton went exploring. Nothing on the cliff caught their eyes, but while bushwhacking back through head-high brush and poison oak, they discovered an unfamiliar but conspicuous shrub. Curious, they took samples and made inquiries. Academy Research Associate Jim Shevock examined specimens at the California Academy of Sciences and concluded that the strange shrub was a new species of Neviusia, a primitive rose previously known only from the southeastern United States. Other populations of the Shasta snow-wreath (N. cliftonii), as Clifton and Taylor named it, soon turned up, including one in a campground at Shasta Lake. Its closest relatives live in Asia. Botanists could be excused for missing a shrub beside a rural highway, even one with white, pom-pom flowers. But in 1996 Taylor returned to a site just off a highway near to Yosemite National Park where he had once noticed some dead, dried plants. Now his timing was better. A showy lily was blooming, casting a pleasant fragrance. It also needed a name and became the Yosemite fawn lily (Erythronium taylori). From the southern coast to the Sierra, in remote places and on well-trodden paths, unknown plants are sprouting up around the state. "To me it's striking that you can still, with reasonable probability, go to a place in California and find a new species," says Taylor. "Taxonomists have their blinkers on, and they assume that the only place this is happening is the tropics." In the Winter 2000 issue of the Annals of the Missouri Botanical Garden, devoted to the theme of "Our Unknown Planet," U.C. Berkeley curator Barbara Ertter compiled a comprehensive account of recent discoveries, rediscoveries, and other "floristic surprises" in North America. California, she found, steals the show. Due to its complex mix of rock types, soils, microclimates, and terrain, California has a reputation as a botanical hotspot. The state is home to both Earth's smallest flowering plant (water-meal, Wolffia globosa) and its largest living thing (giant sequoia, Sequoiadendron giganteum). A report in the February 24 issue of Nature confirmed the Golden State's status; a team of ecologists from Oxford and Conservation International included the California Floristic Province among the top 25 "areas featuring exceptional concentrations of endemic species and experiencing exceptional loss of habitat." Of some 4,800 plant species in the California Floristic Province (which extends north to Gold Beach, Oregon and south to Ensenada, Mexico), 2,500 occur nowhere else on Earth. Moreover, the region's vegetation has been reduced to roughly a quarter of its original extent. (The same study found that the Tropical Andes had the highest number of endemic plants and vertebrates on Earth, including ten times more plant species than the California Floristic Province, so there's some justification for botanists jetting to the tropics.) Still, Taylor and Shevock see no end in sight for botanical discoveries in California. They've plotted the curve, and the trend is definitely up. About ten new plant species turn up statewide in a given year, a number that has stayed steady since the Gold Rush. Taylor thinks that there may be several hundred species yet to be found in California, and many of those will no doubt prove to be endemic—and rare. "If we have 300 or 400 plants that remain to be discovered in California," he says, "many of them are going to be instant endangered species." That was the case with the Ventura Marsh milk-vetch. In June 1997, wildlife biologist Kate Symonds was touring an oil waste dump site outside Oxnard, that had been proposed for a housing development. Noticing an unfamiliar plant with woolly leaves and clumps of cream flowers, she collected a specimen for her U.S. Fish and Wildlife Service colleague, Tim Thomas. He excitedly identified the plant as Astragalus pycnostachyus var. lanosissimus. The species hadn't been seen for 30 years, since the only population, at nearby McGrath State Beach, had been mowed over. Botanists had been looking all over for it, but mostly in its natural salt marsh environment. "We didn't look at the [dump] site because we didn't think that was appropriate habitat," says consulting botanist David Magney. Soil from the beach may have been carried to the dump site, but somehow nearly 400 plants appeared in this unlikely setting. Isolated from high tides and surrounded by hungry snails and rabbits, the milk-vetch population fell by nearly half, says Magney. Attempts to start new populations with plants grown from seed are underway at Carpinteria Salt Marsh Reserve and Coal Oil Point. Meanwhile, Magney's petition to make the milk-vetch a candidate for the state endangered list was approved in the spring, and the California Native Plant Society has sued to block development on the rediscovery site. Last summer, two biologists surveying for California gnatcatchers atop a grassy mesa in Ventura County stopped to examine a plant. After conferring with a botanical key, the biologists realized that they were the first to see the San Fernando Valley spineflower (Choryzanthe parryi var. fernandina) in 60 years. The land owner, hoping to expand an adjacent residential resort, has not allowed further monitoring, but the City of Calabasas has begun efforts to have the plant considered for state and federal protection. Magney would like to see an amendment to the Endangered Species Act that provides automatic protection when any species thought extinct resurfaces. "Usually when they're rediscovered it's because somebody wants to destroy the habitat," he says. When Ertter presented her floristic surprises paper at the Missouri Botanical Garden in late 1998, one of the Garden's botanists, Ihsan Al-Shehbaz, alerted her to an entirely new plant genus from California, known from a single specimen that he had just received. Right off Interstate-5 in Kings County, on another site slated for construction, a botanist had collected the plant in 1994 and mistook it for a common weed. As a name for the new genus, Al-Shehbaz adopted Ertter's suggestion of Twisselmannia, in honor of local rancher Ernest Twisselmann. Decades earlier, Twisselmann had approached Academy curator John Thomas Howell to find out what plant was poisoning his cattle. Howell's enthusiasm proved contagious, and the rancher became an avocational botanist and authority on the southern San Joaquin Valley flora. If these stories suggest that new plants lurk behind every rock, Jim Shevock thinks the odds of stumbling across floral surprises increase the further one gets from roads, trails, and the abodes of botanists. In 1996, Shevock, then a U.S. Forest Service botanist and now associate regional director for the National Park Service, and colleague Dana York explored a vertical fin of marble jutting above the Kings River in Sequoia National Forest. They knew that the rock type was rare for this part of the southern Sierra and that the plants included many species more at home in the Mojave desert or on the east side of the mountains. And, Shevock adds, "By looking in the herbarium we knew that no botanist had been there." Before long they had encountered three new species: Heterotheca monarchensis, Gilia yorkii, and a buckwheat yet to be named. It's not often that anyone bags three unknown species in a day. But although Shevock is something of a ringer, with over 20 Sierran plant discoveries under his belt and seven species named after him, he says that "just about anyone with a keen eye and a willingness to learn the flora can make a contribution to science. It doesn't take Ph.D.s to do this stuff." Taylor and Ertter agree that amateurs play a vital role, but all lament the limited academic support to train new systematic botanists and to treat the work of field naturalists like an apprenticeship. The apparent rush of new finds at some point involves those who have spent many years learning and looking at landscapes. It takes a trained taxonomist to verify each claim. The latest hot prospect, likely a new genus, is an elusive salmon-colored "buttercup" from Yosemite, known only from a photograph and a pressed sprig in a backpacker's wildflower book. When the photo and fragment stumped Dieter Wilken of the Santa Barbara Botanic Garden, he called Shevock. Shevock had never seen anything like it and knew it was new. They accompanied the hiker to the high-elevation trail where he had found the plant the year before but could not locate another. Shevock returned again last fall and failed to find it, but he'll be back looking as soon as the snow melts. "It's a great mystery," he says. "It's clearly nothing that we've ever seen in California, and we've pretty well ruled it out from all the Asian floras, too." Says Ertter, "That's our Holy Grail right now. Blake Edgar is Senior Editor of California Wild. |
Summer 2000
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