Buttonweeds

Annual Buttonweed Annual Buttonweed Yellow Buttonweed Yellow Buttonweed

What are they?

The buttonweeds are a group of small and perhaps easily overlooked species that are members of the daisy family (Asteraceae). They are species that mostly evolved in the southern hemisphere and look rather different to our native plants, but closer inspection reveals features common to the daisy family. The button-like flowerheads are typical of the family in consisting of a flat disk upon which sits a mass of small, tightly packed, yellow florets, with the whole surounded beneath by small, green bracts called phyllaries. This arrangement is just like that of our Common Daisy and all that is missing is the ring of narrow, white petals (or ligules) around the outside.

Where are they found?

These species are relatively new arrivals to our region and are thus still rather uncommon. However, Yellow Buttonweed favours open ground in wetlands, while other species are appearing as urban weeds in pavement cracks or where spreading out vegetatively from neighbouring gardens.

Identification

Buttonweeds are low growing plants, often with creeping stems that root in at the nodes. They have pinnate or deeply lobed leaves and tiny flowers carried in tight, button-like heads. The species can be told apart fairly easily by flower colour, combined with details of the leaf shape and hairiness.



Yellow Buttonweed      Cotula coronopifolia

Of uncertain origin but probably native to the southern hemisphere. A recent introduction to East Anglia, possibly from Europe where it is long-established as an invasive species. Becoming established in coastal grazing marshes in Norfolk and scattered elsewhere. Flowers July to August. Flowerheads relatively large for this group, growing up to 12mm in diameter; leaves with bases sheathing the stems and the whole plant is slightly succulent.

Yellow Buttonweed Yellow Buttonweed Yellow Buttonweed Yellow Buttonweed
Habit
Habit
Flowerhead
Phyllaries
Yellow Buttonweed Yellow Buttonweed
Leaf
Leaf bases suround stem


Annual Buttonweed      Cotula australis

Introduced to the UK from Australia and New Zealand with imported wool products but it is unclear how this species recently turned up in Norfolk as a pavement weed in North Walsham. Flowers July to August. A small, wiry-stemmed annual plant with tiny leaves that are typically on 1cm or so long. Flowerheads small, 3-7mm in diameter. A very easily overlooked plant which may prove to be present as an urban weed elsewhere in the region.

Annual Buttonweed Annual Buttonweed Annual Buttonweed Annual Buttonweed
Habit
Flowerhead
Flowerhead
Leaf


Hairless Leptinella      Cotula dioica

Introduced to the UK from New Zealand as a garden curiosity and recently found spreading onto roadsides from neighbouring properties in NE Norfolk. Flowers July to August. A creeping plant that forms lawn-like mats and spreads vegetatively, often without flowering. Leaves 2-3cm long, slightly succulent and distinctively covered in sunken glands.

Hairless Leptinella Hairless Leptinella Hairless Leptinella
Habit
Leaf
Leaf close-up