Ever wonder why redwood sorrel (Oxalis oregano) leaves appear to wilt in the sun?  The leaves fold downwards when sun flecks shine onto patches of this tiny plant that carpets the coast redwood forest floor.  This is a protective response because this shade-loving plant will get sunburned with prolonged exposure to sunlight.

What is remarkable about this to me is that the plant isn’t actually wilting (involuntary collapse) and is instead actively moving its leaves, similarly to how a venus fly-trap plant closes its trap quickly to catch flies.

Hmmmm, so then why does redwood sorrel also fold its leaves downwards at night when there isn’t any sun at all??? A question to ponder as you hike through the redwoods next time!