Oxalis oreganaRedwood Sorrel
Oxalis oregana is native to the Coast Redwood and Douglas Fir forests of the western United States and Canada. A perennial ground cover, it has three leaflets that are heart shaped and look much like clover. It prefers to grow and flower in deep shade. In gardens, it requires summer watering to look its best. Blooming mainly in the spring, the flowers range from pink to white.
In direct sunlight, the leaves of Oxalis oregana fold down from a horizontal to a vertical position. When conditions become shadier, the leaves re-open. This response happens so quickly, it is observable to the human eye. Watch this time-lapsed video of Oxalis triangularis, "going to sleep" in response to increased light.
Oxalis oregana, like other members of the Oxalis genus, are highly sensitive to changes in touch as well as sunlight. Test it out on your next vist to the Redwood Grove.
The genus Oxalis is from the Greek "Oxys", meaning sour, and the edible leaves do have a sour, tangy taste. They contain oxalic acid, which can be toxic if eaten in large amounts.
Containing some of the world's worst weeds, two members of the Oxalis genus in particular have given it a bad name. O. pre-caprae, known by the common name Bermuda buttercup (even though it comes from South Africa) is known to take over a garden. When pioneering California botanist Lester Roundtree was asked how to deal with O. pre-caprae, she replied, "You move."
Also familiar to gardeners, is the invasive O. corniculata, originally from southern Europe. It has tiny green and bronzy red foliage with yellow flowers.
According to Christian writings, St. Patrick used the shamrock to explain the trinity. Even though it is not known which plant was actually the true shamrock, today some Oxalis are given the common name, shamrock.
Oxalis oregana can be found in the Redwood Grove (Bed 48.)
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