Marin’s rare, endangered plants
Marin’s rare and endangered plants are recognized globally
Did public you open know space that much land was of Marin’s designated in 1988 by the United Nations as the Golden Gate Biosphere Reserve? Marin’s ecosystem is described therein as “Evergreen sclerophyllous woodland and Grasslands to marine/coastal.” Decoding that mouthful, sclerophyllous refers to hard leaf vegetation typically found in Mediterranean climates characterized by dry summers and wet winters. Marin’s dynamic and stunningly beautiful landscape is replete with locally rare species of plants that serve an important role in preserving the diversity of species.
The California Native Plant Society (CNPS) maintains a rare plant list. When the die-off of a species is severe enough, it gets designated as endangered. A rare species is one that can be broadly distributed but never abundant where located. Plants found in a specific habitat and nowhere else are called endemic. California has more than 5,000 native plants, about half of which are endemic. Some endemics are rare, threatened or endangered.
Because ecosystems are built around interaction webs in which every species has the potential to influence another species, local extinctions matter. In Marin, the climate, substratum and topography produce different conditions resulting in different plant communities often not very far from each other. It turns out that many of California’s rare plants are restricted to serpentine soils. Scientists are still studying how plant-microbe interactions contribute to plant survival on serpentine and nonserpentine soil. Here is a bit of backstory on three plant species in Marin County considered rare, threatened or endangered. Poking up on Mount Tamalpais there is Streptanthus batrachopus, the Tamalpais jewel flower, distinct from the Tiburon jewel flower. Marin Flora describes the rare little Tamalpais jewel flowers as 2 to 4 inches tall with flower petals tinged in reddish violet or purple. A member of the mustard family, it blooms in May and June and according to CNPS, likely supports five butterflies and moths. This endemic has been the search subject of the Rare
Plant Treasure Hunt, a programsponsored by CNPS to get people excited about conservation of rare plants.
On the Tiburon Peninsula’s Ring Mountain, a rare, threatened or endangered plant is Calochortus tiburonensis, a Mariposa lily only discovered in 1971. Usually, there is a sharp change in vegetation from oaks and tall grasses found in nonserpentine soil to small wildflowers and sparse trees in serpentine soil. Here in the serpentine soil among the grasses is the Tiburon mariposa lily; a bulb-forming perennial herb in the lily family (Liliaceae). It grows to about 20 inches tall and produces two to three flowers at the end of each branch. The flowers appear inMay and June and are light yellow-green with reddish to purplish-brown markings and long slender hairs edging the petals.
In areas near Tomales Bay, grows the rare, threatened or endangered Raiche’s red ribbons; Clarkia concinna ssp. raichei. More than 70 species of Clarkia are found in California. Clarkias are named after Capt. William Clark of the Lewis and Clark Expedition. This rare plant was discovered by California botanist Roger Raiche and is one of few annual Marin endemic species. It blooms in April and May; its red calyx segments united under pink petals.
For years, Raiche was in charge of the California collection at the UC BotanicalGarden at Berkeley and developed the extraordinary serpentine garden where you can findmore than 200 rare California plants.
When I teach elementary schoolchildren about soil, seed and plant science, I also teach an appreciation for our natural world with the mantra, “We love the Earth because we care for it. We care for the Earth because we love it.”
The environmental diversity and botanical interest of Marin County is recognized globally. We do much when we care and preserve our diverse habitats and native species like jewel flowers, Mariposa lilies and Clarkias.
The University of California Marin Master Gardeners are sponsored by UC Cooperative Extension. For questions about gardening, plant pests or diseases, call 415- 473- 4204 from9 a.m. to noon, and 1 to 4 p.m. weekdays, bring in samples or pictures to 1682 Novato Blvd., Suite 150B, Novato, or email helpdesk@ marinmg.org.