California's narrow-leaved Milkweed has narrow leaves and a wider native range and a whole lot more garden tolerance than most of the other native species. Asclepias fascicularis is a perennial with three foot tall stem and large (but narrow) five inch leaves, and a five inch or so flower cluster. In our area, this plant is covered with monarch caterpillars during the summer. The Orioles use the dead stems for nests the next spring. (The matter looks like fiberglass.) Milkweeds need sun (less flowers in the shade) and can be quite drought tolerant, plant; mulch heavily,or better yet, plant next to boulder, water well first month and ignore. Asclepias fascicularis can tolerate some pretty awful coastal clays that are sour bogs in winter and salty toast in summer. Native from Southeast Washington and adjacent Idaho through California, Oregon, into Baja California and west into Nevada.