Sorghum halepense
Common name
Johnson grass
Family
Poaceae
Flora category
Vascular – Exotic
Structural class
Grasses
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
SORHAL
Conservation status
Not applicable
Detailed description
Root system freely branching, fibrous. Rhizomes stout, creeping with purple spots, usually with scales at the nodes. Stems erect, stout, from 0.45–1.8 m or more tall. Leaves alternate, simple, smooth 15–50 cm long, about 1.3–3.8 cm wide. Panicles large, purplish, hairy (Wax, Fawcett and Isely 1981).
Life cycle
Reproduces by seeds or rhizome fragments during cultivation (Department of Conservation 1998). Seed nearly 3 mm long, oval, reddish-brown, marked with fine lines on surface, bearing a conspicuous awn easily broken off (Wax, Fawcett and Isely 1981). Dispersed bywind, water, on the coats of animals, being ingested by birds and cattle, or in contaminated seeds and feed stocks (Department of Conservation 1998).
Year naturalised
1946
Origin
Mediterranean
Tolerances
The foliage is killed by frost but rhizomes can tolerate 2 days with soil temperatures of -3 to -5C (Department of Conservation 1998)
References and further reading
Wax LM, Fawcett RS, Isley D, eds. 1981. Weeds of the North Central States. University of Illinois at Urbana-Champaign College of Agriculture, Illinois, USA. 303 p.