to traprock soils of southern Queensland
with poorer native grass.
Forest bluegrass (Bothriochloa
bladhii) is a natural component of the better speargrass country, but
subspecies glabra cv. Swan is an introduced species. Swan has moderate spring
vigour, and persists under heavy grazing despite being well eaten by cattle.
Although this leafy perennial was first selected on the infertile
traprock soils of southern Queensland, it is more widely adapted.
Swan produces a fluffy small, but high quality, seed in late March, and can
spread from seed and short rhizomes into run-down native pastues of pitted
bluegrass (Bothriochloa decipiens).
While the seed head is not affected by disease, the leaves can be attacked by
leaf rust (Puccinia spp.) late in the season.