Tuesday, 16 April 2013

Can you tell grader grass from kangaroo grass?


Grader grass (Themeda quadrivalvis) is an annual grass and declared weed in the NT. Stock graze young plants but older plants are undesirable. It out-competes native grasses and is likely to increase fuel loads and fire intensities in savannas. It grows on a variety of soil types including cracking clays, and is currently within a rainfall zone of 450mm to more than 2000mm.

Grader grass is similar to native Themeda species such as kangaroo grass.  Kangaroo grass is generally smaller (usually growing to about 1m in height) and has a brown rather than golden appearance when mature. The two species are most reliably distinguished by the size of the spikelets and the nature of the hairs on their seed heads. Grader grass has smaller spikelets (4-7mm long) with conspicuous hairs on the seed head, while kangaroo grass spikelets are 8-14mm long and seed heads are either hairless or with fine hairs. Grader grass height and robustness of grader grass plants is rainfall and fertility dependent, varying between 40cm and more than 2m, but is typically 1-1.5m.


Grader grass, declared weed and undesirable plant

Second image of Grader Grass, declared weed
Native Kangaroo Grass


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