ADVENTIVES AND ALIENS: Symphyotrichum squamatum in Broadmayne, Dorset
Symphyotrichum squamatum in Broadmayne, Dorset ROBIN WALLS
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or the first time, my daughter and I embarked on a BSBI New Year Plant Hunt. On 2 January 2021 we recorded in three monads covering my village and the next one, notching up 46 species in flower and recording many more not in flower. This seems a respectable total, but there was one plant I could not identify, which made the whole exercise very worthwhile. Thinking it might be an Erigeron/Conyza and probably alien, I sent pictures to Martin Rand and Matt Berry both of whom responded quickly that it was Symphyotrichum squamatum (Spreng.) G.L. Nesom (Saltmarsh Aster). This was new to me and unrecognised on the DDb until I entered the older name, Aster squamatus. This confirmed it as a first for Dorset (v.c. 9) and very rare in Britain and Ireland. The plant looks several years old, although Stace (2019) describes it as annual/biennial. I must have walked past it several times without giving it a second glance. Either it has escaped the attention of the tidy villagers or it is a beneficiary of Covid-19 disrupting normal spraying services. Although well over a metre tall, it is an unassuming plant and only likely to attract the attention of nerdy botanists (or ones desperate for anything in flower), so very probably overlooked in southern Britain. As a South American species that has naturalised in southern Europe, it may be a species that will spread northwards in coming years.
Reference
Stace, C.A. 2019. New Flora of the British Isles (4th edn). C & M Floristics, Middlewood Green, Suffolk.
Robin M. Walls Vice-county Recorder for Dorset (v.c. 9) 10 Old Brickfields, Broadmayne, Dorchester DT2 8UY robin@rmwalls.plus.com
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BSBI NEWS 147 | April 2021
Single plant of Symphyotrichum squamatum (Saltmarsh Aster) on a street in Broadmayne, Dorchester (v.c. 9), January 2021 (top) and close-up showing phyllaries (bottom). Robin Walls
