Many rare plants thrive in Santa Clara County Parks. Here, plants are protected from development, habitat fragmentation and other threats. We hope that you may discover and enjoy these beautiful plants on your journeys through Santa Clara County Parks.
California’s myriad combinations of soils, geography, and microclimates have given rise to plant species uniquely adapted to flourish in specific habitats. This landscape diversity creates numerous species but can also contribute to a plant’s rarity. As an example, 95 different species of manzanitas flourish in California, each with unique adaptations to their particular home site. Manzanitas growing in dry, hot areas possess stomas, pores that control the amount of water released during transpiration, only on the bottom of their leaves minimizing water lost during the day. Manzanitas found in shadier habitats have stoma on both sides on their leaves. Manzanitas living in fire-prone chaparral often have burls at the base of their trunks; these burls contains dormant buds which will start to grow if the parent manzanitas are destroyed by fire. Manzanitas have diversified and speciated to live in serpentine or sandstone, redwood forests or chaparral, from coastal to inland sites, and from sunny sites to shady forest edges. About half of California’s ninety-five manzanita species are considered rare due to California’s landscape diversity.
A plant can also be rare because it may depend upon an uncommon pollinator, or it has a poor dispersal method, or because much of its habitat has been converted or fragmented by humans. Other plants will become increasingly rare due to climate change. We can look at a couple of California natives such as bush anemone, Carpenteria californica, Monterey Pine, Pinus radiata, and the Coast Redwood, Sequoia sempervirens, as illustrations of plants whose distribution and numbers have shrunk as the state’s climate has turned drier and warmer. These plants, once more broadly distributed, have retreated to their current ranges in response to dramatic climatic change.