Since my last post about coast redwoods (see “Redwood Longevity” from 10-14-18) Leonard and I spent several days amid the coast redwoods (Sequoia sempervirens) on the Northern California Coast. On this trip I collected some mature redwood cones. While staring at the redwood canopy high above my head and wishing I could photograph the awl-shaped needles, Leonard found a fallen spray of the very needles I wanted.
Coast redwood needles (leaves) are linear with no petioles and pointed tips. Dark green on top with two rows of whitish stomata on the lower surface, redwood needles appear to be arranged in flat sprays to facilitate the capture of sunlight.
However, high above the ground in the upper canopy temperatures are higher and often conditions are drier. Since redwoods need almost constant moisture, needles in the upper canopy, particularly on cone-bearing branches, are awl-like and resemble giant sequoia foliage. The awl-like needles have a low evaporative surface and help the tree retain moisture.
Coast redwood trees have both male and female flowers. The male flowers and their remnants are like small tufts throughout the tree. They are borne singly on short terminal or auxiliary stalks. Female flowers and cones occur only at the terminal ends of twigs on the far upper branches of the tree. Updrafts move the pollen to fertilize the female cones. The umbrella-like cone scales are arranged in a spiral pattern about the core. Coast redwood cones mature and open in one season releasing thousands of seeds, most of which are infertile or will never germinate.
These photographs were taken along the Hatton Trail in Jedediah Smith Redwoods State Park, Del Norte County CA.