Catsear

Scientific name: Hypochaeris radicata
  • Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

  • Catsear has basal rosettes from which flower shoots grow in spring
  • It is a perennial, sending up new flowering shoots each year
  • The winter rosette is often multi-crowned and is made up of thick, hairy, dull-green, toothed leaves; the rosette rises from a stout taproot
  • Large, solitary dandelion-like flower heads, 2.5 – 4 cm across, appear at the end of tall, solid, sparingly branched, leafless stems
  • Readily distinguished from the other similar species, hawksbeard and hawkbit, by its leaves, which are covered in the short hairs that give the plant its name
  • A very common weed of lawns but also common in grassland, pastures, sand dunes and river beds.

Similar weeds

  • All three species (hawksbeard, catsear and hawkbit) have dandelion-like flowers, and can therefore be confused with dandelion (Taraxacum officinale) and with each other. The true dandelion (Taraxacum officinale) is dealt with on a separate Pestweb page
  • All have basal rosettes from which flower shoots grow in spring
  • Catsear and hawkbit (and dandelion) are perennial, sending up new flowering shoots each year. Hawksbeard, by contrast, has an annual or biennial life history.
  • Hawkbit (Leontodon taraxacoides) is a perennial species, sending up new flower shoots from the rosette in spring
  • Flowers are large (up to 3 cm across) and solitary, borne at the top of solid, leafless, unbranched stems
  • Readily distinguished from the other species and the true dandelion by the unbranched solid flower stem
  • The winter rosette is made up of narrow, shallowly lobed leaves covered in hairs that are forked at their tips (a hand-lens may help!)
  • Slender to stout root, but this species does not have a long taproot.
  • Hawksbeard (Crepis capillaris) is an annual or biennial species
  • Small flowers (about 1.5 to 2 cm across) are arranged in loose clusters at the top of leafy stems
  • Readily distinguished from the other species by its thin, nearly hairless leaves and branched flower stems
  • The winter rosette is made up of thin, smooth, almost hairless, lobed leaves
  • The rosette rises from a taproot and dies after one or two years.

The true dandelion (Taraxacum officinale),is distinguished by its single large, bright golden-yellow flower head, 3-5 cm in diameter, borne at the top of a relatively short, leafless, hollow stem containing milky sap. Its leaves bleed white sap if broken and it has a thick, fleshy taproot that will regrow from severed pieces.

Similar but less common species

  • Three other species of Crepis – Crepis foetida, Crepis setosa, and Crepis vesicaria are found in New Zealand, but the first of these is of extremely limited distribution. Crepis setosa (bristly hawkweed) has rough-hairy leaves, leafy stems and beaked seeds and is sometimes common on roadsides and waste places in a few areas of the North and South Islands. Crepis vesicaria (beaked hawksbeard) has thicker, hairier leaves and beaked seeds and is found in lucerne and hay crops, pasture, unmown roadsides and waste places, mostly on the east side of both islands.
  • One other species of Hypochaeris found in New Zealand is Hypochaeris glabra (smooth catsear). Smooth catsear is quite rare. It is a smaller plant, an annual, and has hairless, red-blotched leaves. The best distinguishing feature between the two species is the row of sharp, more or less flattened hairs on the mid-rib of the involucral bracts (the tiny green leaves at the base of the flower head). Smooth catsear is found scattered throughout the country in grasslands, pasture, dunes, gardens and waste areas.
  • Another species of Leontodon – autumnalis (autumn hawkbit) occurs here but it is also rare. It has shiny narrow rosette leaves that are often deeply lobed and are either hairless or with simple (unforked) hairs. There is more than one flower head per stem and it has a stout rootstock. It occurs in pasture, waste land, costal sand and river beds in higher rainfall areas of Otago and Southland.

Origin

  • Catsear originated in Europe and north Africa
  • It appeared in New Zealand in the early days of European settlement, presumably brought here as a contaminant in pasture seed, in the vegetable stuffing of mattresses, or in imported hay and straw.

Life cycle

  • Catsear is a perennial, with new flowering stems arising from the rosette in the spring every year
  • It is a member of the daisy family and has an umbrella-like pappus attached to the wind-dispersed seed.

Benefits

  • In the presence of less palatable pasture species catsear can be much sought after by sheep
  • Its deep rooted taproot helps it to survive in drought conditions
  • Catsear leaves are sometimes used in parts of Europe as a pot-herb or a salad vegetable.

Impact on crops

  • Catsear is rarely found in annual crops but can be serious problems in perennial crops such as lucerne. It sometimes appears in cultivated gardens and is common in lawns.

Impact on pasture

  • It is found in pasture and, at high density, could interfere with the productivity of grasses and clovers
  • It often has the greatest impact in lawns where it looks unsightly, both as flattened rosettes in winter and as tall-growing flower stalks over summer. 

Impact on the natural environment

  • Catsear is usually found in grassland, waste places or on bare soil but can also be found along paths and clearings in bush where it may interfere with the regeneration of native species.

Grazing management

  • Catsear is readily eaten by sheep and is rarely found in sheep paddocks
  • Maintaining a dense pasture by sowing appropriate grasses and clovers for the area, and grazing the pasture to maintain density will reduce the chances of this flat weed becoming established.

Chemical control

  • In pastures herbicides containing 2,4-D, clopyralid, dicamba, MCPA, or commercial mixtures containing two or more of these, will give good or adequate control of this species. Clopyralid and dicamba are especially damaging to clovers and should not usually be used except for spot application
  • In lawns, several commercial herbicide mixtures advertised for broad leaf weed control will give good control
  • Care must be taken with herbicides containing clopyralid as it does not degrade in compost. Therefore lawn clippings MUST NOT be used in compost bins for at least 6 months after clopyralid application as the compost itself will kill broad-leaved plants when used in the garden.

Integrated control

  • Dense, well-fertilised competitive pastures will deter germination of weedy species
  • Herbicide application in early spring will then give effective control.

  • Popay I, Champion P, James T 2010. An illustrated guide to common weeds of New Zealand. New Zealand Plant Protection Society, Christchurch, New Zealand. 416 p.