AMERICAN SKUNK-CABBAGE

Lysichiton americanus

Arum Family [Araceae]

Flowers:
month8apr month8april month8may

Berries: berryZpossible        berryZred  (highly poisonous)
berry8jul berry8july berry8aug berry8sep berry8sept berry8oct berry8nov

status
statusZneophyte
 
flower
flower8yellow
 
inner
inner8cream
 
morph
morph8asymmetric
 
petals
petalsZ1
 
stem
stem8round
 
smell
smell8evil smell8foul smell8skunk smell8awful smell8obnoxious
evil
toxicity
toxicityZmedium
 

20th April 2013, a boggy garden, Moray Firth, Scotland. Photo: © Douglas G. Miller
Spreads like wild-fire in boggy ground if it gains a foothold.


20th April 2013, a boggy garden, Moray Firth, Scotland. Photo: © Douglas G. Miller
Very similar to Lords-and-Ladies but with a bright yellow spathe.


20th April 2013, a boggy garden, Moray Firth, Scotland. Photo: © Douglas G. Miller
One flower apiece on a single stalk. The single spadix within the spathe is green.


20th April 2013, a boggy garden, Moray Firth, Scotland. Photo: © Douglas G. Miller
Unlike the other Arums, the top part of the spadix is covered in very coarse and cream-coloured protuberances, being the flowers (which are smooth on other Arums).


21st April 2013, a bog, Buzzards Valley, Tiverton, Devon. Photo: © Jeremy Cushing
Leaves are short-stalked, large and oblong. Showing the rear of the spathe on right-hand flower.


21st April 2013, a bog, Buzzards Valley, Tiverton, Devon. Photo: © Jeremy Cushing
The flowers are cream-coloured and protrude slightly. The multitude of tiny flowers themselves open from the bottom of the spadix upwards.


2nd June 2013, stream below Muncaster Castle, Ravenglass, Cumbria. Photo: © RWD
Following the course of a stream. In the Summer as the plant grows larger, the long upright leaves tend to hide the fruiting spadix within (the yellow spathes having long since withered).


10th May 2013, gardens, Muncaster Castle, Ravenglass, Cumbria. Photo: © RWD
Back in mid-May: With large erect light-green leathery leaves in a basal rosette it is not un-like Wild Radish. Four yellow spathes can be seen, there are more hidden within the leaves.


10th May 2013, gardens, Muncaster Castle, Ravenglass, Cumbria. Photo: © RWD
The yellow spathe wilts then decays as the spadix grows larger.


10th May 2013, gardens, Muncaster Castle, Ravenglass, Cumbria. Photo: © RWD
The spathe is not di-similar to the flower spike of a Great Plantain or Sweet Flag.


2nd April 2014, Nymans Garden, South Park Lodge, Lower Beeding, Horsham, West Sussex Photo: © Jan McKinnell
Four pale-yellow stamens protrude slightly from each flower on the spadix.


10th May 2013, gardens, Muncaster Castle, Ravenglass, Cumbria. Photo: © RWD
Un-like many other Arums the flowers are bisexual, with both male and female parts present. The perianth has four parts, the ovary (the oval projections) has two chambers.


Could be mis-identified as : Rare Lords-and-Ladies (Arum italicum) which also has a yellow spathe, but the spadix is also yellow and nearly smooth.

Some similarities to : Asian Skunk-cabbage (Lysichiton camtschatcensis) which is shorter overall with grey-green leaves and has a broader and shorter white spathe and shorter green spadix which is virtually scentless. Both species (Asian and American) are used as ornamental plants from where they can easily escape along watercourses where they become a major problem. The specimens of American Skunk-cabbage on the stream just below the gardens of Muncaster Castle probably escaped from the garden where they might once have been grown as ornamental plants, and possibly still are, there are specimens still to be found within easy sight of the castle itself (see photos above).

Some resemblance to : Lords-and-Ladies (Arum maculata), (which has a greenish-yellow turning brownish spathe with a velvety brown spadix), Arum Lily (Zantedeschia aethiopica) (which has a white spathe and velvety yellow spadix) and Dragon Arum (Dracunculus vulgaris) (which has a frilly beetroot-coloured spathe and also smells awful) to which they are all related (although many are in differing genera).

Hybridizes with: Asian Skunk-Cabbage (Lysichiton camtschatcensis) to produce Hybrid Swamp Lantern (Lysichiton × hortensis) but that has white flowers which lack aroma and occurs in cultivation.

Uniquely identifiable characteristics

Distinguishing Feature : The foul smell, the yellow spadix with pimply green/cream spadix. Unlike most other arums, the spadix eventually out-grows the spathe and peeks out slightly above it.

No relation to : Wild Cabbage (Brassica oleracea) [a plant with similar name but belonging to a differing family].

It is a non-native and listed as a problem plant of shallow wet and marshy places and still waters because it spread un-controllably in damp areas. It spreads both by underground rhizomes and by seed, but is very slow to establish, not flowering until in the 6th year. It is frequently planted beside streams and ornamental lakes and maybe later thrown out because it has spread too much. At Muncaster Gardens in Ravenglass the seeds must have flowed downstream for 500 metres for it has escaped the grounds, naturalised near the stream channel and is about to enter the River Esk lower down if it has not already done so. It dies back in winter. The curled leaves emerge at about the same time as do the flowers; the leaves growing upright to 1m and up to 1.5m long.

It is called Skunk-cabbage because it has a very strong smell which some describe as 'evil' which others might describe as foul, awful, obnoxious or possibly 'skunky'. Cultivated varieties have had much of the obnoxious smell bred out. When in flower Lysichiton species do not produce heat (as does Lords-and-Ladies - but which does not belong to this genus).

The berries are red and form on the spadix where the flowers were in summer. The flower spike looks similar to that of Sweet Flag (Acorus calamus) but that is far taller and the spike emerges from a tight opening in the stem.

It is moderately poisonous containing raphide crystals of Oxalic Acid which are so sharp and narrow as to easily penetrate and rupture individual cells causing lysis; it is thus a mechanical poison - oxalic acid is not very soluble in water. Death is a possibility if a lot has been consumed.


  Lysichiton americanus  ⇐ Global Aspect ⇒ Araceae  

Distribution
 family8Arum family8Araceae

 BSBI maps
genus8Lysichiton
Lysichiton
(Skunk-Cabbages)

AMERICAN SKUNK-CABBAGE

Lysichiton americanus

Arum Family [Araceae]