Overview
Pilea pumila is an annual herb 4-24 inches (10-60 cm) tall with smooth, translucent, watery green stems that glisten when wet, the source of the name clearweed. The opposite leaves are ovate, 1-4 inches (2.5-10 cm) long, thin, glossy, coarsely toothed, and three-veined, on slender stalks, with no stinging hairs despite the plant being a relative of the nettles. From midsummer to fall, tiny greenish flowers crowd into short branched clusters in the leaf axils, the male and female flowers mixed in the same cluster. The flowers are wind-pollinated and have no petals, and the female flowers ripen into small flattened seeds that the plant flicks outward as the stamens snap open. It grows in moist, shaded, fertile ground in floodplains, ravines, seeps, stream banks, and damp woods across eastern North America, often in dense low carpets. The fleshy stems wilt fast in sun or drought. One trade-off is heavy self-sowing, since each plant scatters many seeds and seedlings fill nearby moist ground the next year.
Native Range
Native to eastern and central North America, from Quebec and Manitoba south to Florida and Texas, with scattered records westward. It grows in moist shaded soils of floodplains, ravines, seeps, stream banks, and rich damp woods.Suggested Uses
Rarely planted on purpose, it appears as a volunteer in moist shade and is noted in native-plant surveys. It serves as a larval host for butterflies such as the question mark and red admiral and as cover in damp ground.How to Identify
Appearance
Size & Dimensions
Height4" - 2'
Width/Spread4" - 1'
Bloom Information
Tiny greenish, petal-less flowers crowd the leaf axils from July to October. Male and female flowers share each cluster and rely on wind for pollination. As they ripen, the male flowers snap open and fling pollen, and seeds drop or are flicked out through fall.
Detailed Descriptions
Foliage Description
Glossy light greenGrowing Conditions
Sun Requirements
Tolerates up to 4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Care & Maintenance
Care Guide
Grows in part to full shade on consistently moist, fertile, humus-rich soils at pH 5.5-7.0, and wilts quickly in sun or dry ground. As a warm-season annual it germinates in spring once soil warms and completes its cycle by frost. It needs no fertilizer or care beyond steady moisture and shade. In gardens it appears as a volunteer in damp shaded beds, where shallow cultivation or hand-pulling of young plants keeps numbers down. Plants pull up easily before they set seed.Pruning
Pruning is not applicable to this annual. Plants are pulled or hoed before the seeds ripen to limit self-sowing. Cut or pulled stems do not regrow.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons
✓ Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
Spring after the last frost in moist shade
Days to Maturity
60–90 days
Plant Spacing
6 inches