Part used: leaves and flowering tops
Hyssopus officinalis L. is a semi-evergreen sub-shrub, native to the Mediterranean region Southern Europe but introduced elsewhere and naturalized on walls in Dorset and in parts of Central Europe. It can be hardy but may not survive winter weather. It is the only representative of the genus in Europe and four subspecies are identified, although their status is not definite. The Flora of Turkey gives one Hyssopus species, Hyssopus officinalis subsp. angustifolius.
Branched, square stems (to 60 cm) bear entire, opposite, narrowly lanceolate leaves with glands on each side. Bright blue flowers, with a characteristic smell, occur from August to October in spikes of dense, whorled clusters of three to seven flowers. The flowers are tubular with a short upper lobe and longer three-lobed lower lip. The tubular calyx is toothed.
Other varieties: White forms and pink forms of hyssop are sometimes found, and Hyssopus officinalis subsp. aristatis is a compact variety with smaller spikes of flowers.
The variability of the volatile oils in hyssop is discussed in an extensive review by Jankovsky & Landa (2002) that also refers to sources in Eastern Europe and Russia. The characteristic odour of hyssop is associated with ketones, in particular pinocamphone and isopinocamphone, but their concentrations vary substantially. A study in Hungary, on seed-grown hyssop from nine different sources, found that concentration of pinocamphone varied from 3 to 50%, concentration of isopinocamphone varied from 5 to 50% and limonene varied from 1 to 60%. A study by Fraternale et al (2004) shows variation associated with site of cultivation. A study by Ozer at al (2005) found that subsp. angustifolia had similar constituents to the main species whereas the studies on var. decumbens and subsp. aristatis found different constituents.
The colour of the flowers is variable. A study on three wild types of Hyssopus officinalis L. with blue, red and white flowers yielded similar total oil concentrations with similar proportions of pinocamphone, isopinocamphone and pinocarvone, whereas a similar study found the same main constituents but could distinguish the phenotypes by the relative proportions of each constituent.
A study in a semi-arid area of northern Iran found that hyssop was tolerant of dry conditions and yield of volatile oil was no higher with irrigation every 7 days than every 21 days. Mean total oil concentration was 1.1% in one year and 0.9% in the next, which is similar to that found in other studies.
Dioscorides (III 25) names his plant hyssopos, but does not describe it since it is ‘a well known herb’, he says, of which there are two main sorts, the mountain and the garden. It is a pity he did not describe it since we thus inherit the odd circumstance that the hyssop he refers to may not be the Hyssopus officinalis used for centuries, which is not an unusual circumstance in itself, but in this case, even where authors dispute legitimacy (and the Renaissance authors could not agree upon this at all),
Dioscorides’ applications are cited regardless, as those of hyssop. The problem stems from references made by Dioscorides describing other herbs in reference to hyssop. It is details of oregano and a plant named ‘chrysocome’ (probably Helichrysum orientate Gaertn., according to Andrews 1961) in Dioscorides that confuse the picture somewhat; the leaf of oregano, he says, is similar to that of hyssop, and further particulars of the flowers or flower heads of the two plants offer more opportunities for debate.
Of the Renaissance authors, Parkinson seems to have a lot to say about it, contending it is the true hyssop of the Arabians but not that of Dioscorides or other Greek authors ‘as all doe acknowledge except Matthiolus’; he continues with alternative suggestions and justifications from various authors but eventually rejects them all. Gerard appends a note to his description of hyssopus parva angustis foliis, dwarf narrow-leaved hyssop, the fifth and last of the hyssops he describes, ‘this is by most writers judged to be the hyssop used by the Arabian physicians, but not that of the Greeks which is nearer to Origanum and Marjerome, as this is to Satureia or Savorie’. Dodoens relies on the testimony of other authors, that it is not the right hyssop of the Ancients ‘as is sufficiently declared by certaine of the best learned writers of these daies’. Dale-champs restricts himself to a simple ‘it is not clear what plant the hyssop of Dioscorides was’. Mattioli puts up a long and stout defence, arguing wrong translations, misassumptions about exact meanings, the leaves of a further plant, ‘onitis’ Onitis heracleoticum, likened by Dioscorides to oregano that correspond clearly to hyssop, the context of hyssop in Dioscorides’ collation, and most convincingly of all, that the familiar hyssop plants possess all the strengths and virtues Dioscorides claims for his, ‘as I have tested’. Fuch’s stance supports Mattioli’s although he is far more concise ‘Those who think that this is not the true hyssop of Dioscorides are in error. For it clearly has leaves like those of oregano, but slightly narrower. Nothing more than this was noted by Dioscorides.’ And from Dioscorides’ text this is a reasonable conclusion to reach. Among the several types of hyssop described by Parkinson is one called ’round leaved hyssop’, in Latin hyssopus foliis origani, i.e. hyssop with leaves of oregano. His claim of hyssop being that of the Arabians but not the Greeks is difficult to follow since Serapio’s narrative (as Parkinson says) likens ysopus to marjoram and then includes Dioscorides’ recommendations exactly. Then, despite all, Parkinson concludes his debate quite surprisingly with ‘Now although the true Hysope of Dioscorides, and the other Greeks, is not yet certainly knowne, yet assuredly this which is knowne, and generally receaved, may safely be used in the stead thereof, untill the true Hysope may be knowne’, and proceeds with consideration of the ‘vertues’ according to Dioscorides. Other dissenters follow suit.
Barker (2001) and Grieve both draw attention to references to hyssop in the Bible. Clearly hyssop was a revered and well-used plant in Jewish ritual, but there is much inconclusive debate on hyssop’s identity in that context.
The identity matter is still not concluded since Beck’s 2004 translation of Dioscorides specifies hyssopos not as Hyssopus ojficinalis but as Satureia graeca L. (syn. Micromeria graeca Benth.), a kind of savory. Intriguingly, Parkinson’s satureia vulgaris, winter savorie, is a ‘…herbe, very like unto Hysope’. So the debate continues… if pressed, I think I would stand with Mattioli.
Andrews (1961) presents a very detailed study on hyssop in the classical era, tracing first the biblical references (this plant is unlikely to be hyssop, he says) through to Greek and Roman uses and later references to these, considering clues from many perspectives – historical, geographical, linguistic, economic and further. He journeys through ezob and its Semantic origins, oregano, sampsuchum, onitis, micromeria and satureia, among others. His conclusion is that modern hyssop is the hyssop of Dioscorides.
Hyssop is a warming plant with application to the lungs and upper respiratory system, ridding cold, hard phlegm, useful for inflammation of the lungs, asthma, old hard cough, catarrh and ear problems. Its recommended use with figs and honey for such indications seems quite apt.
The decoction as a gargle for sore throats, with or without the addition of honey Its use for the digestive system too seems in little doubt, for a cold stomach and nutritive organs, as a carminative, gentle purgative, with some influence on the liver. If Pliny’s observations are applied, then it is good as an oxymel here, or with figs again following Dioscorides. Where the above problems are combined, particularly with nervous conditions, hyssop’s effects on the nervous system may prove extrabeneficial. Externally the infusion may be tried for bruises, likewise an infusion or decoction mixed with honey for wounds, but the tradition is less definitive here. Dosage: The British Herbal Pharmacopoeia recommends -4 g three times a day of dried aerial parts.
Monoterpenes: beta-pinene 4-9%; oxygenated monoterpenes: bornyl acetate 3-4%, borneol 4%; ketones:
isopinocamphone 47-58%, pinocamphone 11-22% (cultivated, Scotland).
Total 0.5%, ketones: pinocamphone 14.1%, isopinocamphone 44.7%; sesquiterpenes: elemol 5.6%, germacrene-D-11 –ol 5.7% (flowering tops, cultivated, Serbia).
Total 1.2%, 21 compounds, monoterpenes 32.3%: pinene 18.4%, limonene 5.5%; oxygenated monoterpenes (including ketones) 60.5%: pinocamphone 49.1 %, isopinocamphone 9.7%; sesquiterpenes 0.35% (grown as annual, India).
subsp. officinalis, monoterpenes: beta-pinene 10.5%, 10.8%; oxygenated monoterpenes: linalool 0.2%, 7.9%; ketones: pinocamphone 34%,18.5%, isopinocamphone 3.2%, 29%, camphor 0.3%, 5.3%. The two figures given for each concentration show that the yield and proportions of each oil was different when plants from the same source were cultivated and then transplanted to two locations at different altitudes in Italy.
subsp. angustifolius, monoterpenes: beta-pinene 10.6; oxygenated monoterpenes: 1,8-cineole 7.2%; ketones: pinocarvone 36.3%, pinocamphone 19.6%, isopinocamphone 5.3% (wild, Turkey).
var. decumbens, monoterpenes: limonene 5.1%; oxygenated monoterpenes: linalool 51.7%, 1,8-cineole 12.3%, (wild, France).
subsp. aristatus, three chemotypes: myrtenol 33% and beta-pinene 19%; 1,8-cineole 23% and beta-pinene 25%; methyl eugenol 44% and limonene 16% (wild, Italy).
Phenolic acids: rosmarinic acid, caffeic acids.
Flowers, total 11.7% (233 plants).
Flavone: diosmin, maximum in leaves, sepals.
Recommendations On Safety
• Do not use the volatile oil internally
Avoid use of the volatile oil externally for adults and do not use in infants.
The epileptogenic action associated with the oil is very unlikely in use of the dried herb as the concentration of volatile oils is low.
Use of oil of hyssop is not recommended because of the potential for high levels of ketones. Millet et al (1981) refer to three cases of convulsions: in a 26-year-old woman after a dose of 10 drops a day for 2 days; in an 18-year-old girl after a dose of 30 drops; and in a 6-year-old girl after a dose of half a teaspoonful of oil. There has been one study showing that oil of hyssop is convulsant in rats, by injection over 130 mg/kg but had no effect at 80 mg/kg. The safety of ketones in oils is reviewed in site on Artemisia absinthium. Tisserand & Balacs (1995) advise that hyssop oil should not be used as an inhalation or in massage. This advice is cautious and would not apply to samples of oils characterized as low in ketones.