Wild cucumber, a similar looking native vine that should be preserved, has slightly hairy, more blue-green leaves; white flowers; and fine curly tendrils. It does not form dense mats.
PERENNIAL PEPPERWEED (Lepidium latifolium) This pretty, dark green plant with tiny white flowers topping erect, dark green stems is a major threat to Bay wetlands, including salt marshes. It crowds out grasses that feed waterfowl and natives necessary for endangered species such as the clapper rail and salt-marsh harvest mouse. It is very difficult to control, as millions of seeds spread through air and water, and rhizomes creep many feet under the soil. A tiny piece of rhizome can start a new plant, even after long drying. Cut stems before they can flower; dig roots; dispose of everything in plastic bags in garbage. DO NOT COMPOST. Please report East Bay sightings to Friends of Five Creeks, f5creeks@aol.com.
GIANT CANE, GIANT REED (Arundo donax) This bamboo-like grass, over 10 feet tall, spreads by rhizomes to form dense colonies that displace all other plants. Arundo takes over streamsides without producing shade needed by fish, and sucks up huge amounts of water. DO NOT PLANT ARUNDO IN YOUR GARDEN. Dig up plants if you can (you may need heavy equipment), or cut stems and immediately apply herbicides directly. Dispose of stems and roots in garbage so they cannot re-root.
Three non-native grasses that displace natives:
RIPGUT BROME, left, can be distinguished from native bromes by the long awn - the thread-like fiber projecting from the seed. In ripgut, the awn is much longer than the seed, 1/2" long or more. As the grass matures, the seeds will be more visible individually, many on each stalk.
ITALIAN RYEGRASS, center, is a shiny-leaved grass whose seeds form a slight zig-zag outline on the sides of the thin, upright flower stalk.
WILD OAT, right, is a tall grass with awns framing heavy, stout individual seeds.
ICE PLANT (Carpobrotus edulis): This low-growing plant has long rooted trailers with succulent, bluish-green leaves often shaded red, and bright pink or yellow flowers,. Near salt water, including marshes near creek mouths, it forms dense mats that crowd out native plants that provide food and shelter for such endangered animals like the salt-marsh harvest mouse and California clapper rail. Pull up trailers by hand or with a fork. Dispose of them where they cannot take root.
CARDOON, ARTICHOKE THISTLE (Cynara cardunculus) Cardoon is dramatic, forming tall fountains of large, gray-green, deeply divided leaves and huge blue-purple thistle-like flowers. It started as a garden vegetable or ornamental. But escaped and gone wild, it develops fierce spines that keep out people and animals. Flowers shed thousands of seeds carried widely on the wind. Wearing heavy gloves, dig up the roots as soon as possible. Don't worry about digging up the wrong plant - all large local thistles are invasive weeds. To prevent spread, cut flowers and buds and dispose of them in sealed bags - even cut, they will form mature seeds. Do not grow cardoon in gardens.
PAMPAS GRASS, JUBATA GRASS (Cortaderia selloana, Cortaderia jubata) These tall grasses (6 feet or more) with dramatic white seed plumes crowd out native vegetation without providing food. They also are a fire hazard, and the seed, carried widely on the wind, spreads more clumps. Dig up clumps (this is difficult once they are large). To prevent spread, cut off plumes and dispose of them in sealed trash. Do not grow these plants in gardens.
ALGERIAN and ENGLISH IVY (Hedera). These woody evergreen vines have leathery, dark-green, three-pointed leaves. Algerian ivy, with pinkish stems and less distinct leaf points, is more invasive than English. These ivies are handsome and tough, but they shade out everything else, climb and kill trees, and provide useful habitat only to rats. Wearing gloves (some people are allergic), pull ivy up roots and all -- dense cover can be rolled up like a rug. Donąt let it root again. On trees, cut woody stems growing up trees and pull off a few feet, so the ivy above will die.
HIMALAYAN BLACKBERRY (Rubus discolor) This common shrub has toothed, divided leaves; long reddish weeping canes that root where they touch ground; pale pink single flowers; edible black berries; and sharp, painful thorns. (Native blackberry, which should be preserved, has dense, almost furry prickles that hardly hurt if you grab them.) Himalayan blackberry provides food for birds and people, and nest spots safe from cats and squirrels. But it takes over large areas if left unchecked. Wearing heavy gloves, cut the canes so you can get close and then dig out the roots, especially woody burls that will sprout new canes. Dispose of where parts cannot root.