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Redshank (Lady's Thumb)

Persicaria maculosa

Summary 9

Persicaria maculosa (syn. Polygonum persicaria) is an annual plant in the knotweed family, Polygonaceae. Common names include lady's thumb,spotted lady's thumb, Jesusplant, and redshank. It is native to Eurasia and present as an introduced and invasive species in North America, where it was first noted in the Great Lakes region in 1843.

Description 10

Erect, 20-100 cm tall, annual, glabrous, simple-branched herb, rooting at the nodes. Stem brownish-reddish brown, glabrous. Leaves 1.0-14.0 x 0.25-3.5 cm, narrowly lanceolate-elliptic, acuminate, glabrous - pubescent, entire, subsessile, often with a large dark blotch near the middle on the dorsal side, petiole 1-3 mm long. Ochreae 0.4-1.75 cm long, ovate, usually hirsute, ciliate or fimbriate, ciliae 0.2-1.75 cm or more long. Inflorescence 2.0-3.0 (-3.5) cm long, many-flowered, pedunculate raceme; peduncle 1-2 cm long, eglandular. Flowers 1.5-2 mm across, pedicel 1.0-2.0 mm long. Ochreolae broadly ovate, ciliate, ciliae quite long, sometimes short. Tepals 5, dark pink-red, eglandular, biseriate, unequal; obovate, obtuse. Stamens 6, filaments long, unequal. Ovary ovoid, rounded, with 2 styles, style free above, fused below; stigma capitate. Nuts (1.8-) 2-2.25 (-2.5) x c. 1.5 mm, biconvex, black, shining, glabrous, enclosed by the perianth.

Habitat and ecology 11

Habitat and Ecology

P. maculosa is a characteristic species of damp muddy habitats, occurring from cattle drinking bays on rivers, through the drawdown zones of large lakes and reservoirs, through damp arable to building sites and damp areas in urban situations.

Systems
  • Terrestrial
  • Freshwater

Sources and Credits

  1. (c) AnneTanne, some rights reserved (CC BY-NC), http://www.flickr.com/photos/78746377@N00/516604786
  2. (c) yasingi, some rights reserved (CC BY-NC)
  3. (c) Park Visitor, some rights reserved (CC BY-NC), uploaded by Park Visitor
  4. (c) Mike Leveille, some rights reserved (CC BY-NC), uploaded by Mike Leveille
  5. (c) Corey Lange, some rights reserved (CC BY-NC), uploaded by Corey Lange
  6. (c) John Steel, some rights reserved (CC BY), uploaded by John Steel
  7. (c) eagleloft, some rights reserved (CC BY-NC), uploaded by eagleloft
  8. (c) David Remsen, some rights reserved (CC BY-NC), https://www.flickr.com/photos/dremsen/21610998311/
  9. Adapted by Kate Wagner from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Persicaria_maculosa
  10. (c) Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/5004075
  11. (c) International Union for Conservation of Nature and Natural Resources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31194570

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