Red Natal Grass

Melinis repens (Willd.) Zizka

Synonyms - Rhynchelytrum repens

Family: Poaceae

Names:

Melinis is Greek for Millet.
Repens is from the Latin repe meaning to creep referring to the creeping habit.

Other Names

Blanketgrass, Holme's Grass, Natal Grass, Natal Redtop, Ruby Grass

Summary:

Red Natal Grass is a tufted perennial grass to 1 m high with narrow leaf blades 50-300 mm long and 3-6 mm wide. The inflorescence is silvery to pinkish purple, open and spreading, hairy with white or reddish hairs. The spikelets are 2.5-6 mm long, densely hairy with long hairs. Each spikelet has 2 florets, the glumes are hairy and the upper glume much longer than the lower one.
Native to South Africa, a sporadic weed of road and rail verges and common near Perth. It flowers from spring to autumn.

Description:

Cotyledons:

One.

First leaves:

Leaves:

Blade - Pale green, sometimes with purple blotches, narrow, linear, 50-300 mm long and 2-10 mm wide, setaceous, tapering to a pointed tip. Flat in cross section and rolled on emergence. Usually hairless or may be covered with short hairs on both surfaces.
Ligule - Hairy ring up to 2 mm long.
Auricles - None.
Sheath - Split, hairy. Falls away from the stem with age

Stems:

Flower stem - Pale green, sometimes with purple blotches, 300-1200 mm tall, slender, simple or branching, smooth, hairless to hairy. Often forms roots at the lower nodes. May have hairs. Erect but often bent at the lower nodes.
Forms an open tussock over a few years.

Flower head:

Open panicle covered in reddish hairs, turning grey with age.
50-200 mm long x 20-100 mm wide, silvery to pinkish purple, open and spreading, hairy with white or reddish hairs. Branchlets and pedicels often very flexuose. Long hairs on pedicel just below the spikelet. Spikelets initially adpressed and spreading later.
The mature florets are clothed in shiny pink to pale red silky hairs.

Flowers:

Spikelets - On 1-10 mm long stalks, solitary, egg shaped to oblong, 2.5-6 mm long x 1.5-2 mm wide, densely hairy with long purple pink or shiny white hairs. Laterally compressed and keeled. Smooth or densely warty (tuberculate). Falls entire. Each spikelet has 2 florets.
Florets - 1-2. Upper one bisexual and smaller than the lower one which is male or empty.
Glumes - Hairy. Upper glume 2.5-6 mm long and much longer than the lower one at 0.5-1.5 mm long. Hairy. Upper glume with a short awn up to 4 mm long
Palea - 2. 2-2.75 mm long, ovate almost equal to the lemma, membranous, 2- ciliate keels. 2 nerved.
Lemma - 2. Similar to upper glume.
Styles - Free, slender the stigmas densely plumose, laterally exerted.

Stamens - 3.
Anthers -

Seeds:

Oblong to elliptical closely held by the palea and lemma. Hilum basal, very small (punctiform). Embryo about half the length of the grain.

Roots:

Fibrous.

Key Characters:

No auricles.
Ligule a short rim of hairs.
Spikelets solitary, 2.5-6 mm long with no involucre (bracts), falls entire, disarticulates below the glumes.
Upper floret bisexual, lower one male or empty
Upper glume membranous, gibbous (inflated on one side) at or below the middle, 2 lobed, finely awned, similar length to spikelet and longer than lower glume.
Lower lemma gibbous at or below the middle, 2 lobed, finely awned.
Adapted from Terry Macfarlane and John Moore.

Biology:

Life cycle:

Tufted perennial grass that forms an open tussock over a few years.
May act as an annual plant in some areas.
Grows rapidly in summer.

Physiology:

Frost sensitive.
Drought tolerant.
Fire tolerant.

Reproduction:

Produces large amounts of seed.

Flowering times:

Spring to autumn in WA.
July to April in Perth.

Seed Biology and Germination:

Vegetative Propagules:

Perennial crown

Hybrids:

Population Dynamics and Dispersal:

Spread by seed and road making machinery.

Origin and History:

Native to South Africa or tropical Africa.

Distribution:

ACT, NSW, QLD, NT, SA, VIC, WA.

Courtesy Australia's Virtual Herbarium.
Common in coastal Queensland and around Perth.

Habitats:

Climate:

Temperate, Mediterranean.

Soil:

Sand, loam granite, gravels.

Plant Associations:

Significance:

Beneficial:

Ornamental. Forage grass but of little value.

Detrimental:

Weed of roadsides, railways, disturbed areas and abandoned banana and pineapple plantations.

Toxicity:

Not recorded as toxic.

Symptoms:

Treatment:

Legislation:

None.

Management and Control:

Establish a competitive pasture (563).
Cultivation and cropping normally provide adequate control.
Prevent seed set. Use of mowing or grazing is usually impractical.
Avoid burning unless follow up treatments can be applied.

Thresholds:

Eradication strategies:

Spray with a grass selective herbicides for a few years (e.g. 5 L/ha Fusilade®128 plus spray oil or 1:100 Fusilade®128 plus spray oil for spot sprays).
Burn, cultivate and graze heavily.
5 L/ha glyphosate450 or 1:100 for spot sprays can be used in non selective situations.
Apply sprays any time the plant is actively growing which is normally spring or autumn.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Molasses Grass (Melinis minutiflora)

Plants of similar appearance:

Veldt Grass (Ehrharta spp.) has similar reddish inflorescences and is another common roadside weed.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P56. Photo.

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra).

Ciba Geigy (1980) Grass Weeds 1. CIBA GEIGY Ltd, Basle, Switzerland. P118. Diagrams.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne).

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Gardner, C.A. (1951) The Flora of Western Australia. Vol 1. Part 1. Gramineae. P274-275. Diagram.

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume . P. Diagram.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P56. Photo.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne). P237. Photo.

Lamp, C.A., Forbes, S.J. and Cade, J.W. (2001). Grasses of Temperate Australia. Revised Edition. (Blooming Books, Melbourne). P208-209. Diagram.

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #643.2.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P985, 971. Diagram.

Moore, J.H. and Wheeler, J.R. (2013). Southern Weeds and their Control. (Second Edition). South Coast NRM and Department of Agriculture and Food Western Australia. P. Photos.

Paczkowska, G. and Chapman, A. (2000). The Western Australia flora: a descriptive catalogue. (Wildflower Society of Western Australia (Inc), the Western Australian Herbarium, CALM and the Botanic Gardens & Parks Authority). P110.

Paterson, J.G. (1977). Grasses in South Western Australia. (Western Australian Department of Agriculture Bulletin 4007). P85. Diagram.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.