Michaelmas Daisies

Last week I went for one of my regular rambles. I headed along the river bank towards Urmston, then into Urmston itself for lunch. Because of the lateness of the season it wasn’t a particularly exciting walk, from a botanical point of view, but it was relaxing and peaceful and the weather was good.

I walked home again by following a rather obscure path along the northern edge of the old Stretford tip. There is a dense tangle of willow scrub in this area and the path is very muddy underfoot. About half way along the path I suddenly came upon sheaves of a tall plant with reddish stems and small, whitish daisy flowers. I recognised this plant as a Michaelmas Daisy (Aster sp.). After consulting my Field Guide (ref. 1) I decided that it was Narrow-leaved Michaelmas Daisy (Aster lanceolatus). This is just one of at least six Michaelmas Daisy species and hybrids which are naturalised aliens in the UK, but are originally native to North America. In that continent A. lanceolatus grows in: “Moist soil in New Brunswick to W. Ontario and Montana, S. to New Jersey, Virginia, Kentucky, Louisiana and Missouri (ref. 2).”

There are around 250 species in the genus Aster, many of them North American. We only have two native species in Britain: Sea Aster (A. tripolium) which is, as the common name suggests, a seaside plant, and Goldilocks Aster (A. linosyris) which is a very rare plant of limestone cliffs of western England and Wales.

Two other of the naturalised North American plants that I have found in the Mersey Valley are: Confused Michaelmas Daisy (A. novi-belgii) and Common Michaelmas Daisy (Aster x salignus - which is the hybrid between A. novi-belgii and A. lanceolatus). The name “Confused Michaelmas Daisy” always makes me laugh – but it should be noted that North American botanists tend to use the more dignified name, “New York Aster” (“novi-belgii” = “new Belgium” - which was an early name for New York). I state, with seeming confidence, that I have found these taxa but they can be difficult to identify and can form complex hybrid swarms – so I don’t actually feel 100% confident in my identifications.

Another American species that is naturalised in Britain, but which I haven’t found in the Mersey Valley yet, is Hairy Michaelmas Daisy (A. novae-angliae). Again, North American botanists use a more dignified name, “New England Aster” – which is, of course, merely the English translation of the scientific name. The following passage from the American gardener, Hal Bruce serves to demonstrate the impact that Asters, and related plants, make in the autumn landscapes of eastern North America (ref. 3):

“Until I took a trip by auto to Toledo, Ohio, in late September, I thought I lived in New England Aster country, but on the coast I have never seen the species in the abundance with which it grows from Pittsburgh west. Meadows, banks, roadsides wet and dry along the Pennsylvania and Ohio turnpikes, were bright, whole fields as purple and gold as Byron’s Assyrian hosts with this aster and various goldenrods.”

Aster novi-belgii was introduced into Britain in 1710 (ref. 4). The name ‘Michaelmas Daisy’ refers to the fact that the plant is in flower on the Feast of St. Michael (29th September). It is thought that this name was probably coined after 1752 following the change to the Gregorian calendar. I am guessing that the other Aster species were probably introduced somewhat later.
Cottage gardeners loved to grow A. novi-belgii with Chrysanthemums (ref. 5) but as every serious gardener knows Michaelmas Daisies (at least the ‘old-fashioned’ kinds) can be invasive and prone to mildew – so many must have been thrown out over the years.

A. novi-belgii and other Michaelmas Daisies are now well established on waste ground, roadsides and railway embankments everywhere, along with their American relatives, the Golden-rods (Solidago spp.).

Interestingly, they are rarely condemned as being invasive aliens - but that’s probably because they flower late in the season, when not much else is in flower, and they also represent an excellent late source of nectar for butterflies and other insects. I’ve often wondered if Michaelmas Daisies and Golden-rods have, in some sense, ‘slotted back’ into similar niches to those that they once occupied (not man-made ones, of course). Perhaps before the last Ice Age we had more species of Aster and Solidago in these islands but they failed to return before the North Sea/English Channel opened up ... but that’s just speculation at present.

Dave Bishop, October 2009

References:

1. ‘Wild Flowers of Britain & Ireland’ by Marjorie Blamey, Richard Fitter and Alastair Fitter, A & C Black, 2003.

2. ‘The Gardener’s Guide to Growing Asters’ by Paul Picton, David & Charles, 1999.

3. ‘How To Grow Wildflowers And Wild Shrubs And Trees In Your Garden’ by Hal Bruce, Alfred A. Knopf, 1976.

4. ‘The Origins of Garden Plants’ by John Fisher, Constable, 1982.

5. ‘The Cottage Garden: Margery Fish At Lambrook Manor’ by Susan Chivers and Suzanne Woloszynska, John Murray, 1990.