Hyssopus officinalis (L.) Pers.

Standardized Common Name: Hyssop

Family: Lamiaceae (Labiatae)

Taxonomy: Hyssopus comprises five Eurasian species; H. officinalis is the only species native to Europe. It is rather variable and four subspecies, which have a variety of species-level synonyms, are recognized. Of these, the most widely distributed and most usually found in commerce is subsp. officinalis, followed probably by subsp. aristatus (Godron) Briq.

Description: Perennial herb. Stems 20–60 cm high, erect, quadrangular, woody at base, with long wand-like branches, nearly glabrous to pubescent with long soft hairs. Leaves opposite, sessile, linear to lanceolate, oblong or elliptical, 1–2.5(–5) cm long, 1–6(–10) mm broad; apex obtuse to broadly acute, base attenuate, margins entire; upper surface bearing round glandular dots; lower surface with prominent midrib, dotted with glands, glabrate to pubescent with long soft hairs, especially on margins and midrib. Inflorescences verticillate, mostly forming terminal spikes. Bracts narrowly lanceolate, acute, to 4 mm long, sometimes awned. Calyx tubular; tube 3–5 mm long, pinkish brown, 15-nerved, glabrous to shortly pubescent; teeth 5, triangular to lanceolate, 1–3 mm long, usually with an apical awn, otherwise acute. Corolla purplish-blue or rarely white, bilabiate, (7–)10–12 mm long, somewhat pubescent; upper lip erect, usually emarginate; lower lip spreading, 3-lobed, with middle lobe largest, emarginate. Stamens 4, protruding from corolla and spreading. Style gynobasic. Fruit 4 nutlets, about 2 mm long.

Parts in Commerce: Leaves and flowers

Identification:

Leaves

• Linear to lanceolate or narrowly elliptical; 1–2.5(–5) cm long
• Base tapering, without petiole
• Apex obtuse to broadly acute
• Margins entire
• Midrib prominent on underside
• Conspicuously glandular-dotted
• Surfaces of dried leaves often appear wrinkled with short ridges and grooves connecting the recessed glands
• Odor and taste strongly aromatic

Flowers

• Calyx tubular, with 5 equal teeth; tube regular to slightly curved, 3–5 mm long, 15-nerved, with short soft hairs
• Calyx teeth (1–)2–3 mm long, lanceolate or triangular, awned or acute
• Corolla purplish blue, (7–)10–12 mm long, bilabiate, with short soft hairs especially near mouth
• Stamens 4, protruding; anthers and upper filaments purplish

Reference:

DeFilipps RA. Hyssopus. In: Tutin TG, Heywood VH, Burges NA, et al., eds. Flora Europaea. Vol. 3. Cambridge: Cambridge University Press; 1972:170–171.

Figure 34: Hyssopus officinalis flower.