Black Horehound

The Mint Family - the Lamiaceae - is composed of some familiar members, most of which have a distinctive smell. The smell may be, to the human nose at least, pleasant, as in the case of lavender (although I have found members of this genus on Madeira which are a bit doubtful). Some have little obvious smell, as with White Dead-nettle,  and some are really quite foul. It is to this category that I must consign Black Horehound, Ballota nigra. (The White Horehound, Marrubium vulgare is a plant I cannot recall ever having seen; it tends to be most frequent near coasts.)

The flowers of Black Horehound. Pit Lane,

Byfield, Northants. 4 July, 2016

In his 1930 flora* George Druce describes Black Horehound as 'viatical'. by which he meant 'growing by the roadside or path'. The word is more or less obsolete now but his use of the word seems perfectly justified, for I have always found it growing beside a track of some kind, particularly near gateways.

I came across it earlier today growing beside Pit Lane - invariably called 'Muddy Lane' - in Byfield, Northants. The photograph shows the flower to have the typical zygomorphic shape of the Lamiaceae, although, where the flower has fallen, the 5-toothed calyx is almost actinomorphic, i.e. with radial symmetry. This is clearly shown in the rather poor photograph below.

Each calyx has five more or less symmetrical teeth.

Byfield. 4 July, 2016

The leaves are somewhat heart-shaped (cordate) and frequently have a creamy white edging. As far as I can establish this is not caused by any other organism and plants otherwise seem healthy.

The leaves of Black Horehound frequently have a pale edging.

Pit Lane, Byfield, Northants. 4 July, 2016

So far, nothing remarkable - but now we come to the smell! The leaves, even when just brushed against, emanate a thoroughly nasty odour, described by some as 'harsh' and by others 'evil'. It is vaguely reminiscent of a related plant, the Hedge Woundwort, Stachys sylvatica.

Hedge Woundwort has a similar unpleasant smell.

Pit Lane, Byfield. 4 July, 2016

Nevertheless, this has not prevented herbalists from claiming that Black Horehound has some useful attributes, being described in my old books as stimulant, antispasmodic and vermifuge.


The name 'horehound' was originally 'hoarhound'; the related White Horehound is covered with a white, woolly coating, like hoar frost. The 'hound' bit seems to be just that - a hound. Why, I don't know.

*The Flora of Northamptonshire by George Claridge Druce


e-mail Tony at: diaea@yahoo.co.uk