Serrated Tussock - Identification LC0175 Department of Primary Industries, Frankston ISSN 1329-833X

October 2004 Serrated tussock - Identification LC0175 Department of Primary Industries, Frankston ISSN 1329-833X

This Landcare Note describes the weed serrated tussock, Nassella trichotoma. See the Landcare Note LC0370 for information on serrated tussock management. Common and scientific names Serrated tussock Nassella trichotoma (Nees) Hack. ex Archav. Family Poaceae (grasses)

Figure 2. Seed. Note long awn, attached off-centre to lemma, hairs on callus covering lower section of lemma, rough upper section of lemma.

Figure 1. Serrated tussock leaves, flowering head, tussock. Figure 3-5 (right). Mature plant showing purplish seed heads drooping to touch the ground. Seed heads in close up. Infestation.

Description Distribution Large, long-lived tussocks approximately 50 cm high, 15 to 25 cm diameter at base. Mature plants have drooping leaves that may extend plant diameter to 50 or 75 cm. Smaller plants on infertile soils (15 cm high). Flowering stems - much-branched, initially erect, up to 95 cm long, twice as long as leaves. Droop at maturity to touch the ground. Shallot-like bases. Usually break off at base after seed set. Purplish soon after flowering, golden when seed is ripe. Leaves - very numerous, thin, fine, 0.5 mm diameter, to 50 cm long, tightly rolled, appearing circular in cross-section, with small serrations, felt by running the leaf between the fingers from the tip to the base. Green in Figure 7. Records of serrated tussock in Victoria. summer, yellow-green in winter, base white. Tips of old leaves bleached, fawn in colour. Distinctive ligule – Lifecycle rounded, white, membranous, hairless, 0.5 to 1 mm long, protrudes vertically at the junction of the leaf blade and the Seeds germinate mostly on bare ground after rain, with the leaf sheath, continuous with sheath margins. Similar native largest germination events in spring. Germination occurs grasses have smaller, differently shaped or hair-fringed also in autumn and winter, and in response to soil ligules. Rolled between thumb and index finger, the leaves disturbance, however seedlings can appear 2 to 4 weeks of native grasses feel as if they have flat edges (although after significant rainfall at any time. If seeds germinate in they may be tightly inrolled). Those of serrated tussock late summer and autumn, and conditions are favourable, roll smoothly, as if cylindrical. Seeds - 1.5 to 2 mm long, they will produce seed in the following summer, but under pale brown to purplish at maturity, basal section with 1.2 some circumstances plants may not flower in the first year. mm long white silky hairs, upper section rough; awn 20 to Flowering may commence in early October but usually 35 mm long, attached off-centre, twisted in lower one third begins in early November. Ripe seed is produced about 8 and rough to touch. Enclosed by 2 purple or reddish- weeks after the flowering stems first emerge. Autumn brown, 6 to 10 mm long bracts (glumes) tapering gradually flowering can occur if plants are prevented from flowering to a point. Roots - Diffuse, wiry, fibrous, mostly in top 20 in spring. If not controlled, an area with scattered plants cm of soil, some deeper. can become a moderately dense infestation after 5 years and a heavy infestation after a further 3 years. Laboratory- stored seed remains viable for 20 years, although viability of seed in a forest reduced to 8% after 13 years. Habitat and land use A wide variety of climates with annual rainfall of 450 to 1000 mm. Not limited by soil type or soil fertility. Favours well-drained areas. Tolerates freezing conditions. Pastures, roadsides, neglected areas, native grassland, grassy woodland, dry coastal vegetation. Figure 6. Seed with glumes attached, and section of leaf blade Dispersal and leaf sheath showing ligule (arrowed): a. serrated tussock; b. silver tussock, Poa labillardierei; c. spear grass, Austrostipa Seeds prolifically, spreads rapidly, seed-heads carried sp.; d. wallaby grass, Austrodanthonia sp. along the ground by wind like tumbleweeds; also by The four other Nassella species naturalised in Victoria moving water, on machinery and equipment and coats of have seeds with a corona (a ring of hardened tissue at the livestock. Seed survives passage through the digestive tract apex of the lemma) like a raised crown or collar encircling of grazing animals, remains viable after 10 days in gut. the base of the awn. Acknowledgements Flowering Period Compiled by Ian Faithfull. Fig. 1 Elizabeth Conabere; Fig. 2 Enid Mayfield; Fig. 3 Malcolm Campbell, NSW Agriculture; Fig. 7 John Weiss.

This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Origin Pampas of South America