Henbane growing in Dorset

Henbane (Hyoscyamus niger) growing on a windy Dorset hillside. 

Henbane (Hyoscyamus niger) has got to be one of the weirdest looking plants there is, certainly in this country. Not only that, all parts of the plant are highly toxic to humans and animals, it smells sickly sweet and it usually only flowers biennially (every two years). With its sticky, long-haired leaves that trap unwary insects, once seen henbane is never forgotten.

Part of the nightshade family Solanaceae, henbane is naturalised in Britain and Ireland. This lowland plant thrives in disturbed ground e.g. amongst badger setts, rabbit warrens, on waste land, along field margins and building sites. It favours dry, calcareous soils – particularly overlying chalk, coastal sandhills, and sandy open areas.

Nationally, henbane is on the decline and is classified as ‘vulnerable’. Its demise is often attributed to farming methods and the use of herbicide.

There are many historical reports of henbane growing in Dorset, but further investigation usually seems to result in finding nothing at all. If, however, anyone reading this knows differently, do let me know. In other southern counties I’ve found a few tiny, spindly plants, but nothing like the rather magnificent plants in my photos.

The henbane growing in Dorset and shown here is possibly the last stronghold in the county. Four years ago and then two years ago there was a lot of it growing in this same spot on a hillside, but in 2022 there were just three plants. Is it climate change, the weather conditions this year (seedlings require a cold, moist period to grow and flower), or perhaps something else altogether? Since dormant seeds can remain viable for about four years, the answer lies in two years’ time when there will hopefully be a lot more plants again.

Hyoscyamus niger henbane

Robust henbane plants growing in the same spot in 2018.

Update May 2024: There are still just three henbane plants left in this location. Sadly, I suspect this is pretty much their last gasp.