Horticulture/Pilea pumila

Pilea pumila, known as Clearweed, Canadian clearweed, Coolwort, or Richweed is an annual plant native to most of North America east of the Rockies. The plants are generally erect, 10 to 70 cm tall, often occurring in large colonies, and are quite common throughout their range both as a woodland plant and a weed of gardens.

Description
The foliage is opposite, simple with dentate margins, wrinkly (with depressed veins), ovate, and with long petioles. Both the leaves and stems are translucent and bright green, turning bright yellow in autumn. The flowers are small, borne in axillary cymes, unisexual with both genders occurring on the same plant, greenish yellow, and pollinated by wind. Flowers bloom from midsummer through early autumn. Fruits (achenes) are green with purple markings. Roots are fibrous, shallow, and adventitious off the stem in moist areas or when in contact with the soil.

Ecology
This plant is most often found in rich, moist soils in both sunny and shaded locations.

Uses
It is sometimes grown as a ground cover for its attractive foliage, but this should be done with caution as the plant easily gets out of control, and can develops long-lasting seed banks if allowed to go to seed. They do form a heavy canopy, and so will keep other weeds down quite effectively.

It can also be grown as forage for deer and goats.