FloraFinder.org
Home   About Us   Want to Help?   FAQ  
Searching   Image Use Biblio

Pilea pumila (L.) A. Gray

 

Clearweed

KingdomPlantaePlants, but not fungi, lichens, or algae
SubkingdomTracheobiontaVascular plants—plants with a “circulatory system” for delivering water and nutrients
DivisionMagnoliophytaFlowering plants, also known as angiosperms
ClassMagnoliopsidaDicotyledons—plants with two initial seed leaves
SubclassRosidaeRoses, legumes, proteas, dogwoods, hydrangeas, mistletoes, euphorbias, grapes, many more
OrderUrticalesIncludes cannabis, nettles, mulberries, elms, others
FamilyUrticaceaeNettle family
GenusPileaMostly succulent herbs; from Greek pilos, “cap” (from the shape of some flower parts)
SpeciespumilaMeans “dwarf”

About plant names...

Clearweed is a North American native, a member of the nettle family.

Plants: Clearweed is 6-24" (15-60 cm) high, with smooth, round stems that are somewhat translucent. These plants resemble other nettles, including stinging nettle, but they lack the hairs that cause the sting.

Leaves: In opposite pairs, each 1-5" (2.5-12 cm) long by ½-2½" (1.3-6.3 cm) wide. Leaves are oval-shaped and coarse-toothed, with three prominent veins and textured leaves. The leaves are bright green, usually shiny, and become yellow in the fall.

Flowers: Both male and female flowers are found on each plant. Individual flowers are ⅛" (3.2 mm) long, greenish-white or greenish-yellow. They drop in narrow bunches from the axils of the upper leaves.

Fruits: Tiny green seeds (achenes) sometimes have black stripes.

 

Pilea pumila (clearweed)

8/22/2012 · Squannacook River Wildlife Area, Townsend, MA
≈ 7 × 4½" (17 × 11 cm) ID is uncertain

Pilea pumila (clearweed)

8/22/2012 · Squannacook River Wildlife Area, Townsend, MA
≈ 9 × 6" (22 × 14 cm) ID is uncertain

Pilea pumila (clearweed)

8/22/2012 · Squannacook River Wildlife Area, Townsend, MA
≈ 6 × 4" (15 × 10 cm) ID is uncertain

See this article by Steve Brill on distinguishing among nettles and related plants. Here are some similar species:
 
Laportea canadensis

Boehmeria cylindrica

Acalypha rhomboidea
Common Name

wood nettle

false nettle

three-seeded mercury
Plant 24-48" (60-121 cm) high. Stems have stiff white hairs that sting if you rub against them. 4-63" (10-160 cm) high, and favor shady wooded areas. Stems are smooth, without the irritating hairs of stinging nettle. 6-24" (15-60 cm) tall, with a stem that is hairless or covered with fine white hairs. Bracts beneath flowers, stems, and leaf undersides turn copper-colored.
Flowers Male flower clusters are white or greenish white, in loose branching clusters. Each flower is less than ⅛" (3.2 mm) across, with 5 petals. They appear from July to September. Flowers occur on straight spikes that emerge from the stem, in clusters of small, inconspicuous green flowers. Each spike is often tipped by a couple of small leaves. Flowers appear from July to August. Flowers are greenish-tan, and tiny—less than ⅛" (3.2 mm) across. They flower from July to October.
Leaves Alternate, up to 4" (10 cm) × 6" (15 cm), egg-shaped, with coarse serrations. Usually opposite or nearly so. They are roughly egg-shaped, with sharp tips and teeth. (More precisely, they are elliptic, lanceolate to broadly ovate.) The leaves are 1¾-7" (5-18 cm) × ¾-4" (2-10 cm). Leaves are alternate, lance-like or oval with sharp tips, 3½" (8.9 cm) × 1" (2.5 cm), with blunt serrations.
Fruit Oblique dry seeds. Spiky little balls. A 3-lobed roughly spherical fruit containing 3 seeds.
Range/ Zones

Habitats Moist woods, streambanks, in rich soils Moist, deciduous woods; wet meadows; swamps, bogs, and mashes Open woods, moist soils, gravel bars, waste ground, roadsides, railroads.
Type Wild Wild Wild

 

 
Urtica dioica ssp. gracilis
You are here
Pilea pumila
Common Name

stinging nettle

clearweed
Plant 24-39" (60-100 cm) high, rarely up to twice that. The entire plant is covered in stinging hairs. 6-24" (15-60 cm) high, with smooth, round, translucent stems. They do not have stinging hairs.
Flowers Plants are monoecious—male staminate flowers appear on the same plants as female pistillate flowers. Male flowers are grayish yellow, with four tepals. Female flowers have four tepals too, but in different-sized pairs. They are gray-green and hairy. The flower clusters resemble catkins. Both male and female flowers are on each plant. Fowers are ⅛" (3.2 mm) long, greenish-white or greenish-yellow, hanging in narrow bunches from the axils of the upper leaves.
Leaves Opposite, oblong, cordate, and serrate (with sawtooth edges). They are 1-6" (3-15 cm) long. Leaves occur in opposite pairs, each 1-5" (2.5-12 cm) long by ½-2½" (1.3-6.3 cm) wide. Leaves are oval-shaped and coarse-toothed, with three prominent veins and textured leaves. The leaves are bright green, usually shiny, and become yellow in the fall.
Fruit Each inner pair of tepals encloses a single deltoid to ovoid seed. Tiny green seeds (achenes) sometimes have black stripes.
Range/ Zones

Habitats River deltas, floodplains, margins of deciduous woodlands, fencerows, and waste places Wet upland or floodplain forests, crevices in rocky canyons, and shady wetlands, streambanks.
Type Wild Wild

 

Online References:

Pilea pumila on Missouriplants.com

Pilea pumila at Illinois Wildflowers

Pilea pumila at the University of Wisconsin's Robert W. Freckmann Herbarium

Pilea pumila on Southeastern Flora, the Southeastern U.S. Plant Identification Resource

Pilea pumila on Ontario Wildflowers

Pilea pumila at the Lady Bird Johnson Wildflower Center

References:

Newcomb, Lawrence, Morrison, Gordon (Illus.), Newcomb’s Wildflower Guide, Little, Brown and Company, 1977, p. 438

Pilea pumila (clearweed)

8/8/2010 · Jeff Smith Trail, Beaver Brook Association Conservation Lands, Rte. 130, Hollis, NH
≈ 4 × 6" (10 × 15 cm) ID is uncertain

Pilea pumila (clearweed)

10/17/2016 · Ice Glen, Stockbridge, MA
≈ 7 × 10" (16 × 24 cm)

Pilea pumila (clearweed)

8/22/2012 · Squannacook River Wildlife Area, Townsend, MA
≈ 9 × 6" (22 × 14 cm) ID is uncertain

Pilea pumila (clearweed)

8/18/2012 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 5 × 8" (13 × 19 cm)

Pilea pumila (clearweed)

9/27/2010 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 6 × 9" (15 × 23 cm) ID is uncertain

Pilea pumila (clearweed)

8/16/2013 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 7 × 10" (16 × 25 cm)

Pilea pumila (clearweed)

8/18/2012 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 5 × 8" (13 × 19 cm)

Pilea pumila description by Thomas H. Kent, last updated 16 Sep 2020.

© FloraFinder.org. All rights reserved.


 

Pilea pumila (clearweed)

9/27/2010 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 8 × 12" (20 × 31 cm) ID is uncertain

Pilea pumila (clearweed)

10/17/2016 · Ice Glen, Stockbridge, MA
≈ 7 × 4½" (18 × 12 cm)

Pilea pumila (clearweed)

8/8/2010 · Jeff Smith Trail, Beaver Brook Association Conservation Lands, Rte. 130, Hollis, NH
≈ 7 × 11" (18 × 28 cm) ID is uncertain

Pilea pumila (clearweed)

8/22/2012 · Squannacook River Wildlife Area, Townsend, MA
≈ 7 × 4½" (17 × 11 cm) ID is uncertain

Pilea pumila (clearweed)

9/29/2010 · Nashua River Rail Trail, Ayer, MA
≈ 12 × 8" (31 × 20 cm) ID is uncertain

Pilea pumila (clearweed)

8/8/2010 · Jeff Smith Trail, Beaver Brook Association Conservation Lands, Rte. 130, Hollis, NH
≈ 7 × 10" (16 × 25 cm) ID is uncertain

Pilea pumila (clearweed)

9/27/2010 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 6 × 9" (15 × 23 cm) ID is uncertain

Range:

About this map...