![]() ![]() In Victoria, spiny emex occurs in small patches of limited distribution in lowland grassland and grassy woodland areas. It has become widespread as a weed of grazing and cropping lands, saleyards, vineyards and neglected areas. Spiny emex prefers sub-humid and semi-arid tropical, sub-tropical and temperate regions mainly on sandy and loamy soils. Although germination can vary markedly from year to year, the total number of seeds in the soil remains relatively constant. Individual plants can produce up to 1100 seeds. Seed from fruit on the soil surface germinates less readily than those covered with 1cm of soil. The fruit from the Spiny emex has a long lifespan in the soil (more than 4 years) but very few seedlings emerge from 10cm deep. New infestations are likely to appear first along tracks, around buildings and at stock watering points. These methods have the ability to spread the seeds over distances of 200m. No matter how it lies on the ground one spine always points upwards, attaching it to almost anything that passes over or is placed on it, particularly shoes, rubber tyres, feet of animals or containers of produce. The fruit is well equipped for dispersal. Infestations of spiny emex can be very dense. Growth and lifecycle Method of reproduction and dispersal Spiny emex fruit changes from green to brown as it ripens.įruit is hard and woody, 7 to 11mm long, triangular in longitudinal cross-section - narrowed at the base, each angle extending into a rigid, sharp spine with 4 pits on each face. Male flowers are in small stalked clusters, while the female flowers are almost sessile (attached directly to its base without a stalk) in the leaf axils. Male and female flowers of spiny emex are separate on the same plant and not conspicuous. Each leaf stalk is surrounded by a membranous sheath at the base. Lower leaves grow on long stalks while others grow on stalks at similar length or shorter than the leaf blades. They are mostly hairless with undulate margins. Spiny emex leaves are triangular to ovate, 3 to 12cm long and 2 to 10cm wide. They are mostly hairless, ribbed, fleshy and purplish in colour at the base and at the nodes. Most stems of spiny emex are prostrate but some become erect when growing among tall plants and may grow to 50cm long. Spiny emex is a semi-prostrate annual herb. Herbaceous plant - Forb (flowering herbaceous plant - not a grass) Description Restricted in the Glenelg Hopkins, West Gippsland, North Central, East Gippsland and Corangamite catchments. Regionally controlled in the Mallee, Goulburn Broken and North East catchments. ![]() Regionally prohibited in the Wimmera, Port Phillip and Western Port catchments. Plant status Catchment management authority boundaries Victorian Government role in invasive plant and animal management Protect our environment from the illegal online trade of noxious weeds Prescribed measures for the control of noxious weeds ![]()
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