Many garden treats awaited me back in our Pennsylvania garden on my return from England, the asters and ipomoeas are amazing, plus one mass of color down on the lake shore which I could see gleaming through the trees. The lakeside was lit up by fiery foliage (click images to enlarge).
And this is not a fallen maple or the foliage of a familiar fall-coloring tree. This is a local native perennial called the swamp loosestrife, Decodon verticillatus. Related to the European invasive the purple loosestrife, swamp loosestrife is a vigorous colonizer along the shore, its reddish arching stems rooting wherever they touch the mud.
In fact it’s a bit of a menace. It grows in wet mud along the bank and spreads out into very shallow water where it makes a tight mass, collects silt, and ends up reducing the extent of the open shallow water that small fish and so many insects enjoy. In recent years I’ve been pulling it out to retain that shallow open water that our many species of dragon flies and damsel flies appreciate. But with the lake so low this year, it’s spreading fast across the newly exposed mud.
But at this time of year it’s fiery fall foliage is quite a sight. Earlier in the season clusters of showy pink flowers line the branches. Ducks east the seed capsules and muskrats eat the fleshy roots and stem bases.
If not for its worrying vigor I’d be suggesting Decodon verticillatus for ponds and lakes back in Britain. In fact just one British nursery seems to sell it – and doesn’t mention its vigor. Perhaps in cooler British summers it’s more restrained.
But it’s interesting that while its European relative is universally derided, the invasive tendencies of this local native go unremarked.