Fleshy, hairless plant of the tidal mud with lilac daisy flowers around a yellow centre in late summer, sometimes lacking the rays altogether
Sea aster, Tripolium pannonicum, formerly Aster tripolium.
Nature · Wildflowers & flowers
Sea aster
Native · flowers Jul–Oct · saltmarsh and estuary mud
Tripolium pannonicum — Asteraceae
Sea aster is the wild Michaelmas daisy of the saltmarsh: a fleshy, hairless perennial with lilac ray florets around a yellow eye, flowering from July into autumn on the upper marsh and creek banks. It is one of the plants that colonise the mud as it dries out, and it is the sole forage of a rare specialist bee and a food for the larvae of a scarce moth. It was long named Aster tripolium.
How to spot them
- ▸Daisy-like flowers with lilac-blue rays around a yellow disc, in loose branched clusters; some plants lack the rays altogether
- ▸Thick, fleshy, hairless, narrow leaves, stalkless up the stem
- ▸Grows in saltmarsh, muddy creek banks and estuary margins, up to about a metre tall
- ▸Flowers July to October, when few other saltmarsh plants are in bloom
- ▸Look-alike: a garden Michaelmas daisy, which is often hairy and grows in ordinary soil; sea aster is fleshy, hairless and confined to salty ground. The rayless form can be mistaken for a groundsel-type plant
How to know it
A rare mining bee of coastal cliffs collects pollen only from this saltmarsh daisy, timing its life to its flowering
Sea aster is the forage of the sea aster mining bee, Colletes halophilus.
The scarce starwort moth has caterpillars that feed on the flowers and seeds of this saltmarsh plant
Sea aster — the larval foodplant of the starwort moth, Cucullia asteris.
On a saltmarsh it grows above the pioneer samphire and cord-grass, alongside sea lavender and sea purslane
Sea aster.
Thick fleshy leaves that store water help this plant live in salty mud and survive tidal flooding
Sea aster — a succulent halophyte.
The wild relative of the Michaelmas daisy, named for the Greek word for star, grows only where salt water reaches
Sea aster; aster = star.
Quick-fire facts
- •Native perennial of saltmarshes, muddy estuaries and creek banks; scientific name Tripolium pannonicum, formerly Aster tripolium
- •Family Asteraceae, the daisy family; 'aster' is Greek for star
- •The sea aster mining bee (Colletes halophilus) is a specialist that forages on sea aster and nests in sandy coastal cliffs and banks
- •The larvae of the starwort moth (Cucullia asteris) feed on sea aster; it is a nationally scarce coastal moth
- •A rayless form (var. discoideus), with no lilac petals, is also common
- •In the saltmarsh sequence it follows samphire and cord-grass, growing with sea purslane and sea lavender (Wildlife Trusts)
- •Its edible leaves have been used as a wild vegetable, and it is studied as a possible salt-tolerant crop
- •Garden Michaelmas daisies are American species of the related genus Symphyotrichum, flowering around 29 September, Michaelmas
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Sources
- The Wildlife Trusts — Saltmarsh and mudflats
- Peer-reviewed paper (PubMed Central) — Harnessing the value of Tripolium pannonicum and Crithmum maritimum halophyte biomass through integrated green biorefinery