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Graminae
Synonyms
Festuca fusca (L.); Leptochloa fusca Kunth; Trioda ambigua
R. Br.; Uralepsis fusca Steud.; U. drummondii.
Common names
Brown beetle grass, brown-flowered swamp grass (Australia).
Description
A glabrous, erect perennial or biennial grass growing to 150
cm, with narrow, convolute leaves when dry, with long sheaths and a jagged
ligule. Panicle narrow, 15-30 cm long with erect branches, the lower ones
long (Turner, 1891). It forms well-rooted tussocks. There appears to be
some variability, some are stoloniferous (Chippendall, 1955). Leaf-blades
are 15-30 cm long and 1-2 mm wide when flattened out, usually more or less
inrolled.
Distribution
Asia, Africa, Australia.
Season of growth
Summer.
Rainfall requirements
It occurs over a wide range from 300-450 mm in western New
South Wales, and in areas of up to 1 000 mm or more in coastal areas. It
is always found in or near water and the seed germinates in it.
Soil requirements
It grows in a wide range of soils, but prefers clay loams or
clays.
Vigour of growth and growth
rhythm
In Australia it grows rapidly in summer, generally flowers
from March to May but also in September-October, and dries off till the
next summer rain.
Palatability
It is a soft, herbaceous grass, very palatable to stock.
Natural habitat
Low, wet ground and brackish swamps, and in artesian water
bore drains.
Tolerance to flooding
Good.
Further reading
Vesey-Fitzgerald, 1963.
Tolerance to salinity
Excellent. It is one of the most salt-tolerant grasses. It
is common on inundated heavy soils of the Murray River flood plain in southern
Australia and in alkaline artesian bore drains in central Australia. At
Cooloota Springs and other bores in the area, it inhabits the salt-encrusted
overflow areas of the bore tanks (Lazarides, 1970). In Central Africa the
beds and verges of alkaline lakes are extremely flat, therefore when the
basin is full, extensive areas tend to be shallowly flooded. This alkaline
swamp is colonized by a single species of grass, Diplachne fusca (L.) Beauv.,
which extends for many kilometres. Growing as a water grass D. fusca remains
green and flowers during the rainless months, provided the ground is flooded.
If the swamp dries up, even for a period of years, as so often happens,
the D. fusca mat remains in occupation and becomes burnt during the dry
season. If man-made fires do not consume the dry mat during the dry season,
lightning frequently ignites the tinder-dry herbage at the onset of the
rains. Even under the stress of a clean burn every year the Diplachne mat
yields to no other association on alkaline soils (Vesey-Fitzgerald, 1963).
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