Drosera rotundifolia: keynotes and uses
Drosera rotundifolia — round-leaved sundew, the small insect-trapping plant of acid bogs — holds one of the most teachable single-symptom slots in the materia medica: the violent, spasmodic, barking cough that comes in rapid bursts and is worse after midnight. Spongia covers the dry croup, Rumex the tickling cough of cold air, and Drosera the deep paroxysmal cough that follows one spasm with the next so quickly the patient can barely draw breath.
The plant and its place in the materia medica
Sundew is a carnivorous perennial of nutrient-poor wetlands, its round leaves fringed with sticky glandular hairs that trap and digest insects. Folk practice used it for coughs long before homeopathy, and its juice contains naphthoquinones. The homeopathic preparation tinctures the fresh whole flowering plant and potentises it through serial dilution and succussion in the standard Hahnemannian method.
Hahnemann introduced Drosera in his Materia Medica Pura and treated it as a leading remedy for whooping cough; Hering, Clarke, and Boericke later fixed its cough picture into the modern shorthand. The remedy has held the same compact clinical niche for two centuries: the deep, paroxysmal, after-midnight cough.
Keynotes
Drosera's picture is narrow and easy to recognise — the spasmodic-cough remedy of the respiratory group. Five features recur across Boericke, Hering, and Clarke with enough consistency to serve as a working checklist.
| Keynote dimension | What the sources record |
|---|---|
| Cough quality | Deep, barking, spasmodic; paroxysms follow one another so fast breath is hard to catch |
| Trigger sensation | Tickling in the larynx as from a feather, crumb, or sulphur fumes |
| Time pattern | Worse on lying down and after midnight; the cough often wakes the patient |
| Severity | So violent it provokes retching, vomiting, or nosebleed; the patient holds the chest or abdomen |
| Modalities | Worse from warmth, talking, laughing, singing, and drinking |
Boericke's shorthand still anchors the picture: a spasmodic, dry, irritating cough in rapid succession, with the after-midnight aggravation as the timing marker. Drosera is reached for when the cough matches that paroxysmal, holding-the-chest quality — not for the loose rattling cough of other remedies.
Indications
Drosera is the remedy for the spasmodic after-midnight cough of whooping-cough type, the deep barking cough that lingers after an acute infection, hoarseness with a tickling larynx, and laryngeal irritation worse from talking or laughing. The customary prescription is Drosera 30C or 200C, often as a single dose, with a watch-and-wait observation window. The remedy is not repeated too freely; a single well-timed dose is the classical instruction.
Drosera against its near neighbours
The spasmodic-cough remedies whose territories adjoin Drosera — Spongia and Rumex — are the ones most often confused with it.
| Dimension | Drosera | Spongia | Rumex |
|---|---|---|---|
| Cough quality | Deep, barking, paroxysms in rapid succession | Dry, sawing, croupy, like a saw through wood | Dry, tickling, incessant from a tickle in the throat-pit |
| Worst time | After midnight; on lying down | Before midnight; on waking | Evening and night; on first lying down |
| Key trigger | Warmth, talking, laughing, drinking | Cold air, excitement, lying with head low | Breathing cold air; the patient covers the mouth |
| Severity marker | Retching, vomiting, holds the chest | Anxiety, sense of suffocation | Cough provoked by even slight temperature change |
The three pictures share the spasmodic dryness; the timing, the trigger, and the way the patient guards the chest are what tell them apart.
Safety
A barking cough with breathing difficulty in a child is a red-flag presentation needing prompt assessment. Breathing distress, cyanosis, high fever, and any cough in an infant under three months sit outside the watch-and-wait window and warrant immediate evaluation.
Finding the rubric
Anyone working a case along these lines can search the rubric directly — typing a phrase like cough spasmodic after midnight into the free repertory returns the remedies the classical sources assign to it, and reading those against the keynotes above is the standard first exercise.
References
Boericke, W. (1927) Pocket Manual of Homoeopathic Materia Medica with Repertory, ninth edition, Philadelphia: Boericke & Tafel; entry on Drosera rotundifolia.
Clarke, J. H. (1900) A Dictionary of Practical Materia Medica, London: Homoeopathic Publishing Company; entry on Drosera rotundifolia.
Hahnemann, S. (1811–1821) Materia Medica Pura, reprint edited by R. E. Dudgeon (1880), London: Hahnemann Publishing; Drosera entry.
Hering, C. (1879–1891) The Guiding Symptoms of our Materia Medica, Philadelphia: Estate of Constantine Hering; entry on Drosera rotundifolia.
Kent, J. T. (1905) Lectures on Homoeopathic Materia Medica, Philadelphia: Boericke & Tafel; chapters on the respiratory remedies Spongia and Rumex.
Krenn, L. and Kartnig, T. (2005) Drosera species — a review of phytochemistry and pharmacology, Scientia Pharmaceutica, 73(3), 91–115.