Polygonum caespitosum (Bristled knotweed Bunchy knotweed Oriental ladysthumb )

Transcription

1 1 of 5 9/21/2007 3:16 PM Home Early Detection IPANE Species Data & Maps Volunteers About the Project Related Information Catalog of Species Search Results :: Catalog of Species Search caespitosum (Bristled knotweed Bunchy knotweed Oriental ladysthumb ) Common Name(s) Full Scientific Name Family Name Common Family Scientific Name Images Synonyms Description Similar Species Reproductive/Dispersal Mechanisms Distribution History of Introduction in New England Habitats in New England Threats Early Warning Notes Management Links Documentation Needs Additional Information References Data Retrieval Maps of New England Plant Distribution COMMON NAME Bristled knotweed Bunchy knotweed Oriental ladysthumb FULL SCIENTIFIC NAME caespitosum Blume FAMILY NAME COMMON Knotweed family FAMILY SCIENTIFIC NAME Polygonaceae IMAGES Habit Ocrea close-up Close-up of flower

2 2 of 5 9/21/2007 3:16 PM Incursion NOMENCLATURE/SYNONYMS Synonyms: None DESCRIPTION Botanical Glossary caespitosum is an herbaceous annual that can reach 1 m (3.2 ft.) in height. The stems can be erect or prostrate, are freely branched and can have a reddish color. The thin, dark green, alternately arranged leaves are lanceolate to elliptic in shape, and measure cm ( in.) long and cm ( in.) wide. The leaves are mostly glabrous, but older leaves can sometimes have hairs on the margins and veins on the lower leaf surface. The ocreae (membranous sheaths surrounding stem) have stiff hairs coming from the top which are 5-10 mm ( in.) long. The small flowers of this plant are dark pink, and are arranged in few to many thin spikes. These spikes measure 2-4 cm ( in.) in length and 5 mm (0.2 in.) across, which is relatively thin for most terrestrial species. The flowers appear from July to October. The trigonous achenes are black, smooth and shiny. They are mm ( in.) in size. Page References Gleason & Cronquist 137, Magee & Ahles 442. See reference section below for full citations. SIMILAR SPECIES pennsylvanicum L. (Pennsylvania smartweed) persicaria L. (Lady's thumb) Character caespitosum pennsylvanicum persicaria Ocrea Fringed, with long hairs measuring 5-10 mm ( in.) No hairs Ciliate, with short hairs measuring 2 mm (0.07 in.) REPRODUCTIVE/DISPERSAL MECHANISMS The seeds of caespitosum are dispersed mechanically.

3 3 of 5 9/21/2007 3:16 PM There is also some indication (Muhlenbach 1979) that railroads have played a role in its dispersal. DISTRIBUTION caespitosum is native to eastern Asia in China, Japan, Korea, India and Malaysia. In the United States it has been reported from Maine to Florida and west to Texas, New Mexico, Kansas, Nebraska and Minnesota. caespitosum has been reported from all the states of New England. HISTORY OF INTRODUCTION IN NEW ENGLAND Though the exact date of introduction is unknown, caespitosum was likely introduced into the North America in the 1920's. It spread rapidly across the northeastern, southeastern and Midwestern parts of the country. By 1959 it had been reported in Missouri as spreading. In 1976, this plant was reported as "new to Vermont and the Champlain Valley" (Zika et al. 1983). Thus, this plant's introduction and spread appear to be fairly recent. HABITATS IN NEW ENGLAND Abandoned Field Agricultural Field Early Successional Forest Edge Floodplain Forest Open Disturbed Area Pasture Railroad Right-of-Way Roadside Vacant Lot Wet Meadow Yard or Garden caespitosum prefers moist soil and can grow in low light situations. It is often found in poor soils and can tolerate a wide range of ph (4.8 to 8). THREATS caespitosum is usually found in highly disturbed situations. However, it has been seen in large, monotypic stands and can tolerate extreme shade and ph. Thus, this plant has the potential to invade shaded natural areas and to outcompete other native species that thrive in moist, shaded habitats. It can be found on ridge tops and open woods, usually near trails. DOCUMENTATION NEEDS

4 4 of 5 9/21/2007 3:16 PM Documentation required: A photograph or mounted snippet of the inflorescence with stem and ocreae Best time for documentation: Summer, fall ADDITIONAL INFORMATION Integrated Taxonomic Information System Taxonomic information PLANTS Database General information and map Connecticut Botanical Society Images and description Virginia Tech Weed Identification Guide Description and images GRIN database Native distribution information NBII Southern Appalachian Information Node References for this species REFERENCES Fernald, M.L Gray's Manual of Botany 8th edition. American Book Company, New York. Gleason, H.A The New Britton and Brown Illustrated Flora of the Northeastern United States and Adjacent Canada. Macmillan Publishing Co., Inc. New York Gleason, H.A. and A.C. Cronquist Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. 2nd ed. New York Botanical Garden, Bronx, New York. Holm, L.G., J.V. Pancho, J.P. Herberger and D.L. Plucknett A Geographical Atlas of World Weeds. John Wiley and Sons, New York, USA. Magee, D.W and H.E. Ahles Flora of the Northeast. University of Massachusetts Press, Amherst. Muhlenbach, V Contributions to the Synanthropic (Adventive) Flora of the Railroads in St. Louis, Missouri, U.S.A. Annals of the Missouri Botanical Garden 66(1): Sultan, S.E., A.M. Wilczek, S.D. Hahn and B.J. Brosi Contrasting Ecological Breadth of Co-Occuring species. Journal of Ecology 86: USDA, NRCS The PLANTS Database, Version 3.1. ( National Plant Data Center, Baton Rouge, LA USA. Wheeler, C.T. and S.A. Mengel Phytophagous insect fauna of perfoliatum, an asiatic weed recently introduced to

5 5 of 5 9/21/2007 3:16 PM Pennsylvania (USA). Annals of the Entomological Society of America 77: Zika, P.F., R.J. Stern and H.E. Ahles Contributions to the Flora of Lake Champlain Valley, New York and Vermont (in Torreya). Bulletin of the Torrey Botanical Club 110(3): DATA RETRIEVAL Select a task by clicking the radio button and then click "Submit Selection." Formatted display as table Export as comma-delimited text file Submit Selection MAPS OF PLANT DISTRIBUTION IN NEW ENGLAND Select a study area by clicking the radio button and then click "Submit Selection." The whole New England area One or more states One or more counties One or more towns (county sub-divisions) Submit Selection :: Site Map :: Contact Us :: Report a Sighting Copyright 2004 University of Connecticut