Menispermum canadense aka Yellow Parilla

Menispermum canadense is a woody vine called Canada moonseed. It sheds its leaves and belongs to the Menispermaceae family. It grows wild from southern Canada to northeastern Mexico. Its sites include woods, thickets, and land along streams. It also grows on bluffs, hillsides, and fence rows. The name moonseed comes from the curved seed in each fruit.

This vine grows fast. It climbs by winding its stems around supports. It has no tendrils but can climb through nearby shrubs. Garden plants reach 8–20 feet [2.4–6.1 metres] long. Their usual spread is 3–6 feet [0.9–1.8 metres]. With no support, stems creep across the soil with no set limit. They form ground cover about 1 foot [0.3 metres] tall. Young stems have slight hair and are green to reddish brown. Older stems lose their hair and turn woody. The broad leaves are simple, with one blade each. They grow in turn along the stem on long stalks. Each has three to seven shallow lobes and smooth edges. Leaf tops are bright green. The undersides are pale and downy.

Small, greenish-white flowers hang among the leaves in loose, branched groups called panicles. Bloom runs from May to July, sometimes into August. Male and female flowers grow on separate plants. Female plants need nearby males to set seed. The fruits are drupes, each with a seed inside a hard shell. They hang in groups that look like grapes. From July to October, they turn blue-black with a pale coating. Each seed has a crescent shape, unlike a grape's round seeds. The dark fruit adds interest. Its likeness to grapes, though, poses a danger.

Grow moonseed in moist soil that drains well. Sandy soils suit it, as do soils with a fair level of fertility. It accepts full sun or part shade, including dappled light. Avoid full sun where summers are hot. Sources place its hardiness within USDA zones 4–8 or 5–8. Rhizomes, or stems below ground, let it spread. Divide plants or grow seeds to make new plants. Give it support to climb, or grow it across woodland banks. Ground cover can help limit soil erosion. It needs no pruning. Cutting it back now and then can control growth.

Sources report no serious problems with pests or disease. Moonseed moth caterpillars cut off leaves, then eat them. A long-horned beetle's larvae bore into the wood. All plant parts are poisonous. The fruit can cause fatal convulsions. The poison affects humans and goats, among other species. There are no known edible uses. Past uses as medicine include root teas and salves. Those records do not make this highly toxic plant safe.