Red Willow (Salix laevigata)

April 2018

Red willowT​he willows along ​Putah Creek are looking fuzzier than usual this time of year. Upon closer inspection, they ​are actually ​adorned in green or yellow ​inflorescences ​(flower clusters) shaped like caterpillars, ​and​ might even be giving off cottony tufts​ of seeds​.

One especially shapely willow tree common to Putah Creek is red willow (Salix laevigata). Red willow is a ​m​edium sized deciduous tree, growing ​up to 40 feet tall from winding trunks. Its red to brownish twigs are flexible and easily snap off at the base, and its glossy green leaves are ​narrow, spear shaped, and pointy at the tip, and are dull gray-green underneath.

​Like all willows, red willow is dioecious, which means it has separate flowers for its male and female parts, and these flowers are housed on different trees. Both types of flowers appear as unshowy, drooping catkins, designed for wind pollination, but the cottony seeds are produced only by the female flowers.

The ability of w​illows ​to grow ​readily​ and quickly in​ heavy, wet soils​, make them useful in restoration for helping minimize soil erosion near waterways​. Like other willows, red willow ​is well adapted to flooding. Branches broken off during disturbance ​​sprout easily to create new plants where they lodge in banks downstream. Restoration practitioners take advantage of this characteristic to encourage establishment of new plants by driving cuttings directly into the soil near water.

Red willowRed willow provides wildlife cover and nesting habitat in the mid​-​story layer ​of the​ riparian forest. In the​ ​spring, insects swarm and feed on willow​ ​nectar and birds feed on the seed. ​It and other native willows serve as host plants for several butterflies, including ​Lorquin’s Admiral (Limenitis lorquini), Willow Hairstreak (Satyrium sylvinus)​, and Mourning Cloak (Nymphalis antiopa)​.​

​Willow​s are an essential basket weaving material for indigenous people of California. Suitable basket materials are produced through burning or regular pruning of the trees. Traditional house frames, fences, sweat lodges, arrow shafts​, and medicines are also created using willow. The pain reliever​ ​aspirin is a synthetic derivative of salicylic​ ​acid, a bitter medicinal compound found in​ ​willow bark​, and the namesake for the family of plants that willows belong to, Salicaceae​.