Details of...
Scientific Name: Persicaria maculosa ( syn. Polygonum persicaria )
Pronunciation: pur-sih-KAIR-ee-uh mak-yoo-LOH-suh
Common Name: smartweed, lady's thumb
Family Name: Polygonaceae
Plant Type: Annual, Invasive plant, Weed (horticultural)
Key ID Features: Erect reddish stems with swollen joints; leaves alternate, lanceolate, usually dark spotted, 3-10 cm long; stipules fused into a stem-enclosing sheath that is loose and fringed with bristly hairs on top; inflorescence a dense spike, often nodding; achenes 2-3 mm long, shiny and almost black.
Course(s): not used (on campus)

Habit: Arching, Open, Spreading, Upright
Form: Irregular, Oval - horizontal
Texture: Medium
Mature Size:
Height:0.4 - 0.7m
Spread:0.6 - 1.0m
Growth Rate:Fast
Origin: Europe
Hardiness Rating: Zone 1: (below -46 C)
Exposure: Filtered shade, Full sun, Part sun/part shade
Soil/ Growing Medium: Well-drained
Water Use: Moderate
Landscape Uses: Erosion control, Fall interest, Fragrance, Group or mass planting, Medicinal plant, Wetland - bogs
Additional Info: Google. Compare to P. lapathifolia (which lack the dark leaf spot) and confirm ID.
smartweed, lady's thumb
Leaf Morphology: Glossary
Form: Simple
Arrangement: Alternate
Texture/ Venation: Heavily veined, Soft flexible
Surfaces: Pubescent
Colour in Fall: Red, Green
Leaf(let) Terms:
Shapes: Elliptic, Lanceolate, Ovate
Apices: Acute
Bases: Cuneate
Margins: Ciliate

Inflorescence Type: Floriferous, Spike
Flower Morphology:Flowers perfect
Number of Petals:0
Corolla Shape:Campanulate
Ovary Position:Superior
Colour (petals): Showy, Pink, White
Flower Scent: Sweet, Fragrant
Flower Time at Peak: Jul, Aug, Sep
Additional Info: Five, petal-like sepals

Fruit Type: Achene
Fruit Colour: Brown
Fruiting Time: Oct, Nov
Additional Info: Not showy

Bark or Stem Colour: Green, Red
Organ Modifications: Runners (or stolons)

Propagation: Division - below ground parts, Seed
Pest Susceptibility: Disease resistant
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