Today is typical September in S. California’s South Bay region. The sun is warm and the humidity rising. In short, it’s a perfect day to wander the shady paths of the Gardena Willows Wetland Preserve.
The Preserve, located in south Gardena, is the last remaining remnant of the Dominguez Slough. This seasonal wetland once covered areas now included in the cities of Gardena, Hawthorn and Carson as well as unincorporated areas of Los Angeles County. The waters of Dominguez Slough once drained into Dominguez Creek and thence to the Los Angeles River and the Pacific Ocean. The water that flows through the Gardena Willows Wetland Preserve today still drains into the Dominguez Channel (formerly Dominguez Creek), the Los Angeles River (also now channelized) and into the Pacific Ocean.
The Dominguez Slough has always been treasured as a cool, shady oasis in the hot Gardena Plain. The trees of the riparian (near water) woodland could be seen for miles as a ribbon of inviting green. The native inhabitants of the South Bay – the Gabrielino-Tongva people – used plants that grew in/around the wetland for food, shelter and other essentials. South Bay settlers enjoyed the shade of the large Willows that grew there and favored the Slough as a place for summer picnics and boating. What made Dominguez Slough so inviting were the large willow, cottonwood and sycamore trees that surrounded the wetland. Amazingly, you can see some of the old Willows even today!
The largest – and oldest - willows in the Preserve are Goodding’s Black Willows (Salix goodingii). This species is native throughout the U.S. Southwest and was named for Leslie Newton Goodding (1880-1967), a botanist and collector. Goodding was one of the first to collect plants in what would later become the West’s famous national parks like the Grand Canyon, Yellowstone and the Great Tetons. The common name ‘Black Willow’ refers to the tree’s bark, which is dark gray when wet. Mature Goodding’s Black Willows can grow to a height and width of 50 feet or more – and we have some large ones in the Preserve. You can see the Black Willows towering above the other vegetation in the picture above.
Willows and other local riparian species are unique in their ability to survive both winter flooding and summer drought. Black Willows usually grow right in the water for at least a few weeks/months in the winter. Most trees would die if their roots were under water for several months, but Goodding’s Willow thrives in these conditions and also survives the dry summer months, when streams and wetlands dry up entirely. But adequate winter moisture to recharge the deep soil water is essential for their survival.
Like many willows, Goodding’s Black Willows are not particularly long-lived. Compared to local native oaks (which live to 500+ years) Black Willows usually live only 50-75 years (though we have a few on the Preserve that are probably closer to 100 years old, with enormous trunks). What is deceptive about willows is that while individual trunks may die, new trunks can arise from old trees. So even a ‘young’ trunk can belong to a much older tree.
Willows are dioecious, which means there are separate male and female trees. We have both on the Preserve - the only way you can tell them apart is when they bloom (more on the sex life of willows in the spring). The leaves of the Goodding’s Black Willow look rather like a peach leaf (see below). They are thin and medium green on both sides. Another large willow in the Preserve – the Arroyo Willow – has thicker leaves that are shiny on top and white underneath. Both lose their leaves in winter.
Humans have used Goodding’s Black and other willows for a long time. Their wood is light and was used for making shelters/homes, cooking utensils (wood spoons) and even wooden legs. Young stems were used in basket-making. Both the leaves and bark were used to make medicinal teas. These teas contained salicin (salicylic acid) which is the active ingredient in aspirin. They were used for pain and fevers – much like aspirin is used today.
September 21, 2012 Constance M. Vadheim (Friends of Gardena Willows Wetland Preserve)