BROOMSEDGE, YELLOW BLUESTEM (Andropogon virginicus)

Hawai‘i-Pacific Weed Risk Assessment Score: 22 (High Risk). Visit Plant Pono for moreBroomsedge fruiting on Midway Atoll information. 

Weed Fire Risk Score = 0.79 (This species is likely a high fire risk in Hawai’i); Visit Pacific Fire Exchange Weed Risk Assessments  for more information

Regulatory Status: Hawaii Noxious Weed List (HAR 68)

Prevention and Control Category: N/A

Description

  • Perennial grass growing in dense tufts, yellowish at base; culms erect, 50-100 cm tall, branching freely from the middle and upper nodes, internodes compressed, up to 4 mm in diameter, hollow but partially pithy, glabrous. Leaves primarily basal; blades up to 35 cm long. Inflorescence branches several from each of the middle and upper nodes, slender and wiry, erect or ascending. Caryopsis brown, ovoid, 1.9-2.4 mm long.
  • Native to eastern North America, now extending into Central America.

ImpactsBroomsedge seedhead with a hand behind it for size reference.

  • Forms continuous cover in boggy, open mesic and dry habitats.
  • Releases highly persistent allelopathic substances.
  • Dead material provides fuel for fires. Increases fire intensity and area burned.
  • Fire-stimulated; cover increases dramatically with each fire.
  • It is dormant during the rainy season, which leads to increased erosion in some areas.
  • Seeds dispersed by wind.

Uses

  • Young plants or regrowth after fire are sometimes grazed, but the palatability and nutrient value of this grass are generally low. Mature plants are unpalatable.

Distribution

Common and often dominant along roadsides and in disturbed dry to mesic forest and shrubland, especially on ridges, 50-1,200 m, on Kaua`i, O`ahu, Moloka`i, Lana`i, Maui and Hawai`i.

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