Family: Asteraceae (daisies)

Status:

Several different species in the daisy family are popularly referred to as dandelions, and all are quite similar in appearance. The most common on the coast is not the true dandelion (Taraxacum officinale), but flatweed or cat’s ear (Hypochaeris radicata). All have the form of a flat or erect-leaved rosette, with deeply lobed leaves spreading from a central point. From this central point one to many flowering stems arise (plants growing in better conditions will produce the most flowering stems). Flower heads are yellow with numerous overlapping "petals". Each "petal" is really a small flower in itself with a single petal-like structure more properly referred to as a ligule. They lack a differently coloured centre such as many daisies have. The seeds of all are carried in typical dandelion "clocks" with each seed having a parachute of white spreading hairs to help its dispersal.

The following are the most commonly seen species:

Cat’s ear or flatweed (Hypochaeris radicata) has bluntly lobed leaves covered in erect bristly hairs. Its flowers are 2-3cm across and are carried on wiry green stems which are smooth and hairless. These stems typically branch from a point about one third to half the height of the stem. Smooth cat’s ear (Hypochaeris glabra) is very similar, but with almost hairless leaves and is generally much smaller in both leaves and flowers.

Lesser hawkbit (Leontodon taraxacoides) also has bluntly lobed bristly leaves, which tend to be narrower and more numerous per plant than those of cat’s ear. The most obvious difference to cat’s ear is that each flower is produced at the end of a single unbranched slender (1mm) wiry stem, many of which arise from the centre of the rosette. It is more commonly found in wet sites than cat’s ear. Flower heads are usually smaller, 1-2cm across.

Dandelion (Taraxacum officinale) is more common in the cooler tableland climate than on the coast. It has hairless to sparsely hairy leaves with sharply tipped, backward-pointing lobes (giving rise to the name dent de lion or lion’s teeth in French, from which the English common name is derived). Like Leontodon the flowers are on single, smooth stems, but the stems are much thicker (3-4mm) and are hollow. The flower heads are large, 3-4cm across. When the flowers are open, the outer layer of the involucral bracts (the many narrow green flaps which enclose the immature flower) are reflexed, or bent backwards towards the stem.

Smooth hawksbeard (Crepis capillaris) is also more common on the tablelands than the coast. It has hairless, pointy-toothed leaves like those of dandelion, but narrower and more delicate. It usually produces a single tall straight hairless flower stem which branches close to the top, carrying a few flowers which are paler yellow and smaller than those of cat’s ear or dandelion. It also has a few small leaves scattered up the flowering stems. If Crepis is mown or grazed, it can produce much shorter, more branched and spreading flowering stems.

Tolpis umbellata (no common name) is a smaller annual weed with grey-green toothed or lobed leaves and flower heads about 1cm across with pale yellow "petals" and a brown centre.

Preferred habitat and impacts
All are weeds of bare ground such as road verges and thrive on disturbance, although cat’s ear is the most widely distributed weed in south-eastern Australia, penetrating even quite undisturbed forest. Leontodon is often found around the edges of wetlands, being tolerant of waterlogged soils.

All are potential invaders of remnant grassy vegetation of farming areas, and of wetland margins. Hypochaeris will invade almost any sort of native vegetation if it includes some areas of bare ground. It can become dominant where there is regular soil disturbance such as grazing. Being flat rosettes, they cover a relatively large area of soil and therefore can suppress native grasses and herbs quite effectively.

Dispersal
Seed is wind-spread, or spread in contaminated soil or hay and other stock feed.

These plants have a common daisy form which is shared by several native herbs. The following are the most similar:

Narrow-leaved picris (Picris angustifolia) is most similar in general appearance to Crepis, having an erect flowering stem which is branched close to the top. Leaves are narrow (to about 1cm) and not very lobed or toothed. Its most conspicuous distinguishing feature is that the leaves and flowering stems are covered in branched T-shaped hairs. The hairiness is very obvious, and the T-shape may be discernible if the plant is held up against a dark backdrop in strong light. The weedy species may have hairy leaves, but none have hairy stems. Picris usually occurs only in undisturbed forest, but may occasionally be found in disturbed situations where roads pass through forest. It is more common in the Snowy Mountains.
Murnong or yam daisy (Microseris spp) is quite similar to Hypochaeris or Leontodon. The photo of cat's ear (on the left) and murnong flowers shows the brown underside of the cat's ear outer "petals", and the fewer clear yellow "petals" of murnog with no brown underside. There are at least two murnong species, an alpine and a lowland one. They differ from the weedy daisies in having very narrow leaves, never more than 15mm wide, and usually less. The leaves are usually more or less parallel sided and may be sparsely toothed. The flower heads have fewer "petals" than those of the weedy species and have the habit of drooping over in bud and again after flowering, but being held erect when the flowers are open. Microseris is not very likely to be found on the south coast, but it does occur on the grassy edges of upland bogs along the top of the coastal escarpment.

Control
It is seldom worth trying to eradicate any of these weedy daisies, unless only a small number of plants of a species not previously present turns up. The bare ground created by either digging them out or use of herbicides is only likely to encourage further proliferation. It is best to discourage them by maintaining a dense, undisturbed cover of native vegetation. However, within small areas it is possible to eradicate new infestations of any of the "dandelions". The most effective method for small numbers is to sever the root below ground with a sharp knife, causing as little soil disturbance as possible, before the plant has a chance to set seed. Remove any flowers and bag for safe disposal (burn or bury deeply).