Skunk Cabbage – The big, the bad and the smelly!

As if that isn’t enough it’s also a bit of a bully. Skunk cabbage (Lysichiton americanus) is also known as American Skunk Cabbage, Eastern Skunk Cabbage and Swamp Lantern all very accurate and descriptive names as we will get onto in a bit. It doesn’t belong in the UK originating from the damp woodlands of the American Pacific Northwest and was first introduced to the UK’s gardens, way back in the early 1900s. There is no doubt as to why – it is spectacular in many ways. An early flowering plant, it adds a magical, Illuminating charm to the dark, dank recesses of early spring in the shady bog garden. It sends up its mottled leaves and distinctive flower from March onwards. First, a cluster of leaves emerges from the soil surrounding the bright, lamp like flower. A sun-yellow cowl or spathe that surrounds a rather phallic cluster of flowers, called a spadix. Both distinctive features place it in the family of plants known as Arum Lillies one of which might be familiar to you. The smaller and native Lords and Ladies or Cuckoo Pint.

Swamp lantern in bloom. The Yellow Spathe is a modified leaf, that wraps around the flower itself, the Spadix.

The bright spathe even resembles a lantern, hence one of it’s common names. The other names refer to it’s odour – a strong, musty, skunk like aroma. Now while not quite as pungent as the mammal after which it is named, it certainly is no rose! The offensive, sweet and fetid odour is familiar to many flowers of this family as they are designed to attract carrion insects to carry out the act of pollination.

The issues is that while it is slow to get going. Once established it is very difficult to get rid of, due to its deep tubers and roots Its seeds are carried by the water and here on the Teign, with at least three separate sources found close to the headwaters, all of which were built as grand country retreats, there is a risk that they could turn up anywhere downstream. At this time of the year, the plants look fairly inoffensive but give those leaves a couple of months and they will unfurl to over a metre in length and up to 70cm wide! Such huge leaves then block any light and smother other native plants and animals. Potentially a big problem. While it hasn’t quite made it onto the baddest of the bad list (that includes notifiable weeds such as Giant Hogweed) it has been classified as an invasive non-native species by the European Union since 2016 in recognition of its highly negative and invasive tendencies.

It was while walking over the upper reaches of the South Teign last week, that a group of us including RTRP Officers Nick Baker, Geoff Stephens local river and fish fan Steve Phelps that we discovered clusters of these plants along a few, rarely visited sections of the river bank. Initially, we came across one or two very stately specimens and then on a wide, wet sandy bank a more sinister gathering of over 30 plants – “looks like we might have to do something about this” said Steve.

Steve Phelps – lets the Skunk Cabbage have it!
Bill Blake in action – is he enjoying this a little too much?

True to his word – Super volunteer Steve returned before the week was out. Armed with knowledge on how to tackle these triffids (provided by the local Invasive species officer for Devon) garden forks, bin bags and some more volunteer ‘grunt’ in the form of Bill Blake. Between them, they did a monster job of up-rooting the aliens, which have been sealed into bags and removed from the site. As with many such subjects – they’re not invasive by accident and often well-meaning folk can unwittingly end up moving the problem to another area. In this case, any roots & tuber fragments can lead to more germinating on the site – so, while every care was taken to remove every fibre, there will almost certainly be some fragments that got away. It will be a task that needs repeating every year until no more are seen at the site. The plants dug up will be left to compost down in a hot black bag, to minimise the risks of any living fragments surviving.

There will almost certainly be more plants that have got away from their original gardens and it’s worth you river watchers keeping an eye open for others when you’re out and about. If you discover any please take a photograph and record their exact position (a six-figure grid reference is ideal) and let us know. Even better if this is the sort of thing you might want to get involved with as a volunteer please contact Geoff Stephens who is coordinating our volunteer programme. Whether you’re interested in river insect (River fly surveys) doing regular water quality checks, fish counting or helping with more hands-on work parties, there is something for everyone and we would love to hear from you and help you to help your river.

Skunk Cabbage ready for secure composting.