Red Pigweed

Oxybasis rubra var. rubra None

Flora Italiana


Flora Italiana

Class
Dicotyledoneae (Dicots)
Family
Amaranthaceae (Amaranth Family)
State Protection
Threatened
Listed as Threatened by New York State: likely to become Endangered in the foreseeable future. For animals, taking, importation, transportation, or possession is prohibited, except under license or permit. For plants, removal or damage without the consent of the landowner is prohibited.
Federal Protection
Not Listed
State Conservation Status Rank
S2
Imperiled in New York - Very vulnerable to disappearing from New York due to rarity or other factors; typically 6 to 20 populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines.
Global Conservation Status Rank
G5
Secure globally - Common in the world; widespread and abundant (but may be rare in some parts of its range).
Contents
  1. Summary
  2. Conservation and Management
  3. Habitat
  4. Range
  5. Identification Comments
  6. Taxonomy
  7. Additional Resources
  8. About This Guide

Summary

Did you know?

This is a widespread, variable species occurring in much of the United States (except the Southeast) and in Europe and Asia. It was first collected in New York by George W. Clinton of the Buffalo herbarium on a visit to Staten Island in 1874.

State Ranking Justification

There are nine existing populations but phragmites may be crowding out plants in some locations. There are 14 historical occurrences, mostly from the early 1900s, and most of these probably did not persist.

Short-term Trends

Most of the existing populations have not been surveyed more than once but the 2 populations that have been resurveyed again have not been found because of the dominance of Phragmites in their habitat.

Long-term Trends

Over the long term there has been a substantial decline in this species as saltmarshes and swales have been ditched, developed, or taken over by Phragmites.

Conservation and Management

Threats

There is a substantial threat from the spread of Phragmites into interdunal swales and saltmarshes where this species grows.

Conservation Strategies and Management Practices

The primary need is to keep Phragmites from invading its habitat. Management needs should be adjusted as new information is obtained from research projects.

Research Needs

Research is needed to develop management techniques that will allow this species to persist and grow. Studies should be done to understand how human manipulation of beaches and saltmarshes affect this species.

Habitat

Habitat

In New York, Red Pigweed has been found along the coast in wet interdunal swales, stony beaches, and the shores of coastal ponds, as well as amongst ship ballast and waste places (New York Natural Heritage Program 2010). Salt marshes (Clemants 1992). Salt marshes and brackish soil (Gleason and Cronquist 1991). Waste ground, shores, and river banks (Voss 1985).

Associated Ecological Communities

  • Brackish interdunal swales* (guide)
    Temporarily tidally flooded temperate marshes in interdunal swales dominated by salt-tolerant graminoids. Individual swales occur as small patches positioned between fore-, primary and secondary dunes in a maritime dunes system, typically on barrier islands.
  • Coastal plain pond shore* (guide)
    The gently sloping shore of a coastal plain pond with seasonally and annually fluctuating water levels. Plants growing on the pond shore vary with water levels. In dry years when water levels are low there is often a dense growth of annual sedges, grasses, and herbs. Submerged and floating-leaved aquatic plants, such as fragrant waterlily and pondweeds, may become "stranded" on the exposed shore. In wet years when the water level is high only a few emergents and floating-leaved aquatics may be noticeable. T
  • Coastal salt pond* (guide)
    A community inhabiting marine shoreline lakes or ponds formed by sandspits that close off a lagoon or bay. The water typically averages brackish or slightly brackish over long periods of time, but may range rapidly from fresh to saline.
  • Dredge spoil wetland*
    A wetland in which the substrate consists of dredge spoils; reedgrass is a characteristic species.
  • Marine dredge spoil shore*
    The wetland community of a constructed, intertidal or subtidal, marine shore in which the substrate is composed of dredge spoils. This community has minimal vegetative cover and relatively low species diversity. Dredge spoil shores provide foraging habitat for terns, gulls, and several shorebirds.
  • Marine intertidal gravel/sand beach (guide)
    A community washed by rough, high-energy waves, with sand or gravel substrates that are well-drained at low tide. These areas are subject to high fluctuations in salinity and moisture. A relatively low diversity community, it is perhaps best characterized by the benthic invertebrate fauna including polychaetes, and amphipods.
  • Maritime freshwater interdunal swales* (guide)
    A mosaic of wetlands that occur in low areas between dunes along the Atlantic coast; the low areas (swales) are formed either by blowouts in the dunes that lower the soil surface to groundwater level, or by the seaward extension of dune fields. Water levels fluctuate seasonally and annually. Sedges and herbs are usually the most abundant types of plants. These wetlands may be quite small (less than 0.25 acre).

* probable association but not confirmed.

Associated Species

  • Amaranthus pumilus (sea-beach amaranth, coast amaranth)
  • Cakile edentula
  • Polygonum glaucum (sea-beach knotweed)

Range

New York State Distribution

This species is mainly restricted to the saline areas of Long Island and the extreme southern Hudson Valley. It is also historically known from the inland salt ponds of Onondaga County. Scattered additional historical records from waste ground in non-saline soils are also reported.

Global Distribution

This small herb occurs in the Northeast United States and northeastern Canada where it is rare. It is scattered throughout the northern Midwest, becoming common from the Dakotas south to New Mexico and out to the West Coast. It is also common from central Canada west to Alaska.

Identification Comments

General Description

Red pigweed is an annual herb up to 80 cm tall with glabrous, angled stems. The leaves are triangular or rhomboid, deeply toothed, and up to 15 cm long. The infloresence consists of many small (5 mm thick) glomerules in axillary spikes, or in larger plants, in terminal panicles. The tiny green flowers have 3 or 4 sepals, 0.8 to 1 mm long and joined at the base. The seeds are held erect, and are shiny, smooth, brown, and 0.6 to 1 mm wide (FNA 2003, Gleason and Cronquist 1991).

Best Life Stage for Proper Identification

Entire plants with flowers or fruit are needed for identification.

Similar Species

In New York there are 3 other species of Chenopodium which are thornless and have non-glandular foliage and erect seeds. Chenopodium glaucum has leaves that are densely white-mealy on the undersides. Chenopodium capitatum has fewer, much larger glomerules (5-15 mm thick) than those of C. rubrum. Chenopodium bonus-henricus, a European introduction, is a perennial species with entire leaves and flowers with 4 to 5 sepals (FNA 2003, Gleason and Cronquist 1991).

Best Time to See

Red Pigweed flowers from mid-May to early September and the fruits persist on the plants into October.

  • Flowering
  • Fruiting

The time of year you would expect to find Red Pigweed flowering and fruiting in New York.

Red Pigweed Images

Taxonomy

Red Pigweed
Oxybasis rubra var. rubra None

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Dicotyledoneae (Dicots)
        • Order Caryophyllales
          • Family Amaranthaceae (Amaranth Family)

Additional Common Names

  • Coast-blite
  • Red Goosefoot

Synonyms

  • Chenopodium chenopodioides (L.) Aellen
  • Chenopodium rubrum L.
  • Chenopodium rubrum var. rubrum

Comments on the Classification

The native status of this species is often questioned.

Additional Resources

Best Identification Reference

Flora of North America Editorial Committee. 2003. Flora of North America North of Mexico, Volume 4, Magnoliophyta: Caryophyllidae, Part 1. Oxford University Press, New York.

Other References

Clemants, Steven E. 1992. Chenopodiaceae and Amaranthaceae of New York State. Bulletin No. 485. New York State Museum. Albany, NY.

Fernald, M. L. 1950. Gray's manual of botany. 8th edition. Corrected printing (1970). D. Van Nostrand Company, New York. 1632 pp.

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

Mitchell, Richard S. and Gordon C. Tucker. 1997. Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No. 490. New York State Museum. Albany, NY. 400 pp.

New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.

New York Natural Heritage Program. 2023. New York Natural Heritage Program Databases. Albany, NY.

Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research http://www.fccdr.usf.edu/. University of South Florida http://www.usf.edu/]. New York Flora Association http://newyork.plantatlas.usf.edu/, Albany, New York

Links

About This Guide

This guide was authored by: Stephen M. Young

Information for this guide was last updated on: September 20, 2012

Please cite this page as:
New York Natural Heritage Program. 2023. Online Conservation Guide for Oxybasis rubra var. rubra. Available from: https://guides.nynhp.org/red-pigweed/. Accessed December 5, 2023.