Arthraxon hispidus, Small Carpgrass

Gardens & Landscapes, Invasive Species October 05, 2012 Print Friendly and PDF

Invasive Species: Arthraxon hispidus, Small Carpgrass

Small carpgrass is an invasive annual grass that was introduced into the United States, either accidentally or by immigrants, from Japan and eastern Asia. The plant stands to 1.5 ft. (0.5 m) tall with oval to lance-shaped leaves. Leaves are 1-3 in. (2.5-7.6 cm) long, 1/5 in. (0.5 cm) wide and have heart-shaped bases. The margins of the leaves have conspicuous hairs. Flowers bloom in early fall and are contained in 1 to several, 1-3 in. (2.5-7.6 cm) long spikes. The seeds are slender and yellowish in color, measuring 0.2 inches (4 mm) long. Small carpgrass inhabits wet areas such as stream banks, flood plains, and shorelines.

What are invasive species and why should we be concerned about them? 


Taxonomy: Scientific and Common Names for This Species

Cyperales > Poaceae > Arthraxon hispidus (Thunb.) Makino

Synonym(s): jointhead arthraxon, hairy jointgrass

Arthraxon hispidus - USDA PLANTS Profile

Distribution Maps

Small carpgrass - The reported distribution of this invasive species across the United States (Source: Invasive Plant Atlas of the United States)

Up-to-the-minute distribution maps and why they are important 

Reporting This Invasive Species

What is the best way and place to report the occurrence of an invasive species? 

 How to report an invasive species sighting to EDDMapS - Early Detection & Distribution Mapping System

EDDMapS - Report an invasive species to EDDMapS.

Cooperative Extension Offices - Find your local Cooperative Extension office on this map provided by USDA.

How to Identify

This invasive species can be identified by looking for the characteristics described in the paragraphs that follow.

Grass

It is an annual that stands to 1.5 ft. (0.5 m) tall with oval to lance-shaped leaves.

Leslie J. Mehrhoff, University of Connecticut, bugwood.org Leslie J. Mehrhoff, University of Connecticut,   bugwood.org

Foliage

Leaves are 1-3 in. (2.5-7.6 cm) long, 1/5 in. (0.5 cm) wide and have heart shaped bases. The margins of the leaves have conspicuous hairs.

Leslie J. Mehrhoff, University of Connecticut,   bugwood.org Leslie J. Mehrhoff, University of Connecticut,   bugwood.org

Flower

Flowers bloom in early fall and are contained in 1 to several, 1-3 in. (2.5-7.6 cm) long spikes.

Leslie J. Mehrhoff, University of Connecticut,   bugwood.org Leslie J. Mehrhoff, University of Connecticut,   bugwood.org

Fruit

The seeds are slender and yellowish in color, measuring 0.2 inches (4 mm)long.

 
Steve Hurst, USDA NRCS PLANTS Databse,  bugwood.org bugwood.org

Native Species That Can Resemble Small Carpgrass

- Images at invasive.org

   
bugwood.org bugwood.org

- Images at invasive.org

   
bugwood.org bugwood.org

Additional Images for Small Carpgrass

Small carpgrass - Images at Invasive.org

Additional Information, Biology, Control and Management Resources

Control and management recommendations vary according to individual circumstances. Location, habitat, weather, and a variety of other conditions are factors that help determine the best treatment choice. To find the safest and most effective treatment for your situation, consult your state's land-grant institution. If you will use chemicals as part of the control process, always refer to the product label.

 

United States Land-Grant University System - Find your land-grant university's college of agriculture, Cooperative Extension office, or other related partner on this map provided by USDA.

Invasive Plant Atlas of New England - University of Connecticut

Weed of the Week - USDA Forest Service

Invasive Plants of Asian Origin Established in the United States and Their Natural Enemies - USDA Forest Service


Connect with us

  • Facebook

Welcome

This is where you can find research-based information from America's land-grant universities enabled by eXtension.org

LOCATE

USDA / NIFA

This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.