Black Horehound

Black Horehound

It is a common, unremarkable member of the mint family with one defining feature – its pungent, rotten smell. This smell, discourages cattle from eating it and gives it a local name of ‘Stinking roger’ in some places.


Black horehound prefers nitrogen rich soil, and so is often found with stinging nettles and dead nettles; Frequently found on wasteland, near water and usually where people have occupied at some point in the past. It likes loose, alkaline soils and survives frosts down to -10oC.

It can be found in most of Europe (including Britain) south and east from Scandanavia to north Africa and the eastern Mediterranean.


A perennial herb in the Lamiaceae family. Erect stems, green nettle-like leaves and small purple mint-family flowers.

Identifying Features

  • Stem – It has herbaceous ascending stems, wooden and branched at bottom. Like other mint family members, it has a square cross-section and is covered in down-folded hairs.
  • Leaves – Leaves are opposite and decussate (alternating opposite pairs, each pair at right angles to the next), and range from oval-lanceolate to heart-shaped, with crenate or dentate border. Dark green and usually hairy, measure 3–8 cm long and 2–6 cm wide, and have 1–3 cm petiole. Upper face is wrinkled, with a net-like vein pattern.
  • Flowers – Organized in clusters around the stem, with 15 to 30 flowers. It has an actinomorphic calyx (length 9–10 mm, width 7 mm), made up by five sepals fused together in a tube with five teeth; and a labiate corolla of 12–13 mm, ranging from pink to pale purple to withish. The corolla consist of a tube of about 6 mm and two lips; the upper one slightly concave (like a hood) and externally hairy; the lower one glabrous, with two minor lateral lobes and a major central bifid lobe. There are four didynamous stamens, running parallel under the upper lip, with glabrous filaments and yellow anthers. Ovary is superior, with a single white style and a 2-parted stigma. Below the calyx there are five filiform bracts, 8 mm long.
  • Fruit – Each fertilized flower produces a group of 5 black nutlets, cylindrical to ovoid, 2 mm long, partially or fully covered by the calyx. The basal end is flat and attached to the receptacle, while the top end is rounded or pointed.




Whilst it is not toxic and will do you no harm, it has a pungent musty, rotten smell and the taste is not much better; Although I have seen people try it and say that they like it!


Black horehound has a long history of herbal use7,8, though is not widely employed in modern herbalism because of its unpleasant flavour. It has a range of medicinal virtues, being especially effective in its action as an antiemetic9. In the past it was often used for treating problems connected with the respiratory system, convulsions, low spirits and the menopause, but present-day authorities differ over whether it was effective in these applications9.

Other uses

None known.

Known Hazards

None known.


Flowers between June and September and is usually gathered when flowering.

Potential Lookalikes

Other members of the mint family, especially dead-nettles, woundworts, etc. Superficially stinging nettles too, but only at a glance.

Mythology and Symbolism

The name Ballota comes from the Greek ballo (to reject), because of the strong offensive odour of the plant; cattle will not eat it. The specific name nigra refers to the black colour of dried leaves.

The common name comes from the Old English words har, meaning “downy or hoary”, and hune, meaning the plant itself. This name refers to the hairs that give the herb its distinctive appearance.


  1. Wikipedia – https://en.wikipedia.org/wiki/Betula_pendula
  2. Woodland Trust – https://www.woodlandtrust.org.uk/visiting-woods/trees-woods-and-wildlife/british-trees/native-trees/silver-birch/
  3. PFAF – https://www.pfaf.org/User/Plant.aspx?LatinName=Betula+pendula
  4. Chiej. R. Encyclopaedia of Medicinal Plants. MacDonald 1984 ISBN 0-356-10541-5
  5. Grieve. A Modern Herbal. Penguin 1984 ISBN 0-14-046-440-9
  6. Bown. D. Encyclopaedia of Herbs and their Uses. Dorling Kindersley, London. 1995 ISBN 0-7513-020-31
  7. Stuart. M. The Encyclopedia of Herbs and Herbalism Orbis Publishing. London. 1979 ISBN 0-85613-067-2
  8. Chevallier. A. The Encyclopedia of Medicinal Plants Dorling Kindersley. London 1996 ISBN 9-780751-303148
  9. Mills. S. Y. The Dictionary of Modern Herbalism.
  10. Plants of the World Online, Royal Botanical Gardens Kew

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