Californian Thistle occurs in most parts of the State although it is somewhat uncommon in the Midlands. It grows most vigorously in the North-West and North-East in areas where the annual rainfall exceeds 1000 mm. It is frequently found throughout the Southern part of the State but in most years it does not develop large vigorous stands, its growth to a large extent being inhibited by the attack of the rust Puccinia obtegens and aphids. Californian Thistle is economically important in pastures and to an increasing extent in crops, particularly irrigated vegetable crops, in certain parts of the State - More...

Cape Weed is distributed throughout Tasmania and is most often seen on light sandy soils. It occurs in pasture and grain crops, sometimes in other crops, and in areas considered to be wasteland. It is extremely prolific in young pastures and cereal crops. An increase in this species of often seen when changing from cattle to sheep. - More...

Cat’s Ear is distributed throughout the State. It occurs in pastures and turf, most crops, and in waste land. It is economically important as a wed in turf and is also strongly competitive in poor quality pasture. Germination occurs mainly in the Autumn and to a lesser extent also in Spring. The cotyledon is 10 to 16 mm long overall with a short merging petiole some 3 to 5 mm long, and is hairless. The seedling has a very short hypocotyl and no epicotyl. - More...

Charlock is widely distributed in the South of the State, but much more localised and restricted in distribution in the Northern half. It appears to be more prevalent on heavy than on light soils, though it is known to be capable of growing on red soils. It is a weed of waste areas and crops, and is of considerable importance, especially in cereals, in the South due to its strong competitive habit and its ability to overgrow and swamp crops. Germination occurs mainly in the Autumn. - More...

Common Cotula is distributed throughout the State. It occurs in waste areas and in towns and occasionally in crops or pasture. It is of limited economic significance. Germination occurs in Autumn and Spring. The cotyledon is small, only 2 to 3 mm long, sessile and hairless. The seedling has a very short hypocotyl and no epicotyl. The first leaves are paired, 15 to 20 mm long with a merging petiole, and have a few long thin hairs on the upper and lower surfaces. The margin is simple. Later leaves grow singly. As the plant grows the leaves become progressively more lobed. The plant develops as a rosette 100 mm to over 300 mm in diameter. - More...

Cotton Thistle is found in the Midlands from Jericho in the South to Launceston in the North, with odd isolated patches in a few other parts of the Stater. It occurs principally in improved pastures, but is also found in crops growing in the infested area. It is strongly competitive. Cotton Thistle is the subject of an eradication campaign. The main germination occurs in late Summer or early Autumn, plants which germinate at this time forming sizeable rosettes before the onset of Winter. Seedlings which germinate in late Autumn or early Winter may suffer a very high natural mortality. Further limited germination occurs in Spring and early Summer. Seedlings which appear before November usually mature and set seed the same season, but those which do not germinate till later generally only form a rosette in their first season and mature in their second. - More...

Dandelion occurs in all parts of the State. It is found in waste areas and in limited numbers in crops, but is mainly important as a weed in turf. Germination occurs in Autumn and to a lesser extent in Spring. The cotyledon is 7 to 12 mm long overall with a short merging petiole, and is hairless. The seedling has a very short hypocotyl and no epicotyl. The first leaves, which arise singly, are 10 to 20 mm long overall with a usually short but distinct petiole. They are hairless and have a dark green shiny surface. Initially leaves have only a few small lobes but as the plant develops the leaves become progressively more lobed and later rosette leaves may be secondarily divided. The lobes are more or less regular and generally backwardly directed. The plant develops as a rosette. - More...

Field Cress is found in many parts of Tasmania, but is somewhat local and restricted in its distributions. It occurs in waste areas and crops, and is capable of being competitive. Germination occurs in Autumn and Spring. - More...

Groundsel is distributed throughout the State. It occurs principally as a weed of waste areas and gardens but may also be found in small numbers in crops. It is of little economic significance. Germination occurs in the Autumn or Spring. The cotyledons are 6 to 13 mm long overall with a short merging petiole 2 to 4 mm long, and are hairless. The plant has a long hypocotyl and a short epicotyl. The leaves develop singly, the fir5st being 15 to 25 mm overall in length and sessile or with a merging petiole. The earliest leaves may have a few or no hairs, but later leaves have numerous multi-cellular hairs on the upper and lower leaf surface. The first leaf usually has a few small lobes while later leaves have many lobes. The plant does not form a rosette. - More...

Hawkbit is State-wide in distribution, occurring in turf and pasture, waste areas, and occasionally in crops. Its greatest importance is as a weed in turf, and it is locally significant as a weed in pasture. It germinates in Autumn and Spring. The cotyledon is 10 to 15 mm overall with a short merging petiole, and is hairless. The seedling has a very short hypocotyl and no epicotyl. The leaves grow singly, the first 15 to 20 mm long with a short merging petiole. It carries scattered hairs on the upper and lower surface many of which are grapnel hairs which have a distinctive shape with a bi- or trifid tip reminiscent of a small grappling iron. The margin carries a few small protuberances. Later leaves reach 120 mm in length with more or less regularly scolloped margins. The tips and lobes frequently curl upwards. Grapnel hairs are present on the upper and lower surfaces. - More...

Hedge Mustard is found in most parts of the State. It is principally a weed of waste areas, though it is not infrequently found in orchards and cereal or vegetable crops. It is moderately competitive and the hard and wiry mature stems can interfere with cereal harvesting. Germination occurs in Autumn and Spring. - More...

Indian Hedge Mustard occurs in all parts of the State, but is generally less common than Hedge Mustard. It is a weed of waste areas and orchards, and occasionally occurs in arable crops. It is of little economic importance. Germination occurs in Autumn and Spring. - More...

Lesser Swinecress occurs throughout the State and is found in waste areas, arable crops, and pasture during the establishment stage. It may also be present in weak established pasture. It is a moderately competitive species, and is a major cause of taint in milk. Germination occurs in Autumn or Spring. - More...

Nodding Thistle is found in many parts of the State but is very localised, having been imported into Tasmania as an impurity in ryegrass seed. It occurs in pasture or in crops sown in areas which have become infested. It is extremely competitive, continuing to grow vigorously and flower throughout the Winter. It is the subject of an eradication campaign in the State. Germination can occur at most times of the year if there is sufficient soil moisture. The cotyledon is 10 to 15 mm long with a short, merging petiole, and is hairless. It normally has a distinct white vein up the centre. - More...

Prickly Sow Thistle occurs in all parts of the State. It is principally a weed of waste areas, though it is often found in small numbers in many crops. Since it is palatable in the young stages it does not normally survive in pasture. Germination occurs in the Spring and Autumn. - More...

Ragwort, once best known as a weed of the North West of the State is also present in the North East, in the South and on the Central Plateau, particularly on the east of the Great Lake. It is still extending its range in areas which offer a suitable habitat. It grows most prolifically where the rainfall is in excess of 1000 mm annually. It is principally a weed of waste and neglected areas and of river flats. Areas in which the forest cover has been removed and not replaced by well managed pasture or crops are particularly vulnerable to invasion. It frequently occurs in pasture but does not normally become important where this is well managed. It is a weed which has attracted a great deal of attention completely out of proportion to its economic importance. Germination occurs in Autumn and Spring depending on locality and seasonal conditions. - More...

Saffron Thistle has been found in isolated patches in several parts of the State. Its greatest importance is as a weed of pasture where the very spiny nature of the mature plant seriously interferes with grazing by sheep or stock. - More...

Shepherd’s Purse occurs throughout the State. It is a common weed of arable crops. It is moderately competitive in young crops, but most soon overgrow it. Germination occurs in Autumn or Spring. - More...

There are two Slender Thistles present in Tasmania which are difficult to distinguish, particularly in the early stages, and are generally considered as one species. Slender Thistles are found in most parts of the State, but are particularly numerous in the Midlands. They occur in pasture, waste areas, and arable crops. They are strongly competitive in pasture and can appear in significant numbers in cereals. The main germination period is the Autumn, though Winter and Spring germination also occurs, more particularly in the Northern half of the State. The germination pattern is greatly influenced by the Autumn rainfall. - More...

Sow Thistle occurs in all parts of the State. It is principally a weed of waste areas but appears infrequently in most crops. Since it is palatable it does not normally survive in pastures. Germination occurs in Spring and Autumn. - More...

Spear Thistle is numerous in all parts of the State. It occurs in pasture and waste areas and in all crops. It can be very competitive in pastures and in parts of the Midlands densely infests large areas. The main germination period is in the Autumn but germination in the Spring and early Summer also occurs regularly. - More...

Variegated Thistle occurs in most parts of the State. It is a large competitive plant capable of completely taking over a pasture or crop. When growing on soils of high ferility or when affected by growth regulator herbicides the leaves can develop a high nitrate concentration which makes the plant toxic to stock. - More...

Hoary Cress occurs in most parts of the State but is most common in the South and South Midlands. It is a major weed along roadsides and railway lines, and occurs commonly in run down pastures and waste areas. It is found in cereal crops and lucerne in some places and can be competitive if present in large numbers. Germination occurs in the Autumn. Propagation via the perennial root stock is probably as, or more, important than spread by seed. - More...

Wild Radish occurs throughout the State in waste areas, and young pastures. It is strongly competitive in all situations and is one of the most important weeds in Tasmania. Germination occurs in Autumn and Spring, continuing through into Summer in irrigated crops. - More...

Wild Turnip occurs throughout the State, but is very much less common in the Midlands than it is in the South or in the North East and North West. It is a major weed in all arable crops, being strongly competitive and capable of overwhelming young or low growing crops. Germination occurs in Autumn and Spring, and continues through the Summer when there is sufficient moisture. - More...

Wireweed is common throughout the State and is a major weed in all arable crops. It is both competitive in the early stages and likely to interfere with harvesting operations in cereals when mature. Germination occurs principally in Spring, continuing through into Summer where moisture permits. - More...