Standardized Common Name: English Lavender

Other Common Names: Common Lavender, Continental Lavender, True Lavender

Family: Lamiaceae (Labiatae)

Taxonomy: Lavandula includes about 30 species, found primarily in warm habitats in the Old World. Seven are native to southern or Mediterranean Europe, including L. angustifolia. Some commonly seen synonyms for this species are L. officinalis Chaix., L. vera DC., and L. spica L. (in part). Lavandula spica, as used in pharmaceutical literature, usually referred not to English lavender but to L. latifolia Medik. (Spike Lavender); since the meaning of L. spica is now wholly ambiguous, that name has been formally rejected and should not be used for either species. The common name “English lavender” is frequently also used for Lavandin (Dutch Lavender), L. ×intermedia Emeric ex Lois., which is a hybrid of L. angustifolia and L. latifolia. Personal observations by [TK: Author] indicate that almost all commercial English Lavender in the United States and United Kingdom is of hybrid origin; the broader definition of English Lavender as including Lavandin should perhaps be accepted in practice as conforming to established custom.

Description: Perennial shrub to >1 m tall. Stems branching, crooked, quadrangular, woolly-pubescent with stellate hairs. Leaves opposite, sessile, lanceolate to oblanceolate or linear, 2–5 cm long, green to grey, pubescent with stellate hairs; margins revolute. Inflorescence a loose terminal spike of 6–10–flowered verticillasters, 2–8 cm long, bracteate, with the lowest whorl separated from the others; bracts (1–)3–8 mm long, rhomboid, acuminate; bracteoles subtending individual flowers tiny, scarious and linear, or absent. Calyx tubular, narrowing near the mouth, 4–7 mm long, 13-veined, bluish-grey to purple, pubescent with large stellate hairs and glands; teeth 5, small, the upper tooth with an obcordate appendage. Corolla bilabiate, tubular, 10–12 mm long, deep blue to purple in upper portion, pubescent; upper lip 2-lobed, lower lip 3-lobed, upper lobes somewhat larger, rounded; lower portion of tube narrowed. Stamens 4, 2 longer, 2 shorter, the filaments attached basally to the corolla tube. Style gynobasic; ovary 4-lobed. Fruit 4 nutlets.

Parts in Commerce: Flowers or flowering spikes

Identification:

Bracts

• Bracts rhomboidal to ovate with an acuminate tip and membranous, normally not linear and leaflike
• Bracteoles beneath individual flowers absent or membranous, linear, <2 mm long (or 2–6 mm long, sometimes branching, in plants of hybrid ancestry)

Calyx

• Tubular, narrowed at mouth, 4–7 mm long
• Bluish to purplish over much of length, with conspicuous branched hairs
• With 13 veins, not 8 or 15
• With 5 small teeth, upper tooth largest and sometimes with visible appendage

Corolla

• Bilabiate, tubular, widening above, with equal lobes
• Blue to purple; generally not deep purple
• 10–12 mm long
• Odor pleasant, characteristic

Adulterants: Most of the seven European species of Lavandula are of some commercial value. All but L. latifolia (Spike Lavender) and L. ×intermedia (Lavandin) can be distinguished without difficulty by floral characters. Spike lavender has corollas that are only 8–10 mm long, and the calyx is grayish, with purple color only at the tips. The bracts are linear rather than rhomboid, but the bracteoles subtending individual flowers are 2–6 mm long and sometimes branched. Some cultivars of L. angustifolia may resemble L. latifolia. Lavandin, the hybrid of the two species, is sterile and is propagated vegetatively. It is generally intermediate in form, often having ovate-rhombic bracts like L. angustifolia but relatively large bracteoles like L. latifolia. As noted above, the sale of hybrid material under the name of English Lavender has become customary, and if it has suitable chemistry (and hence aroma, etc.), there seems to be no reason to object.

References:

Applequist WL. Proposal to reject the name Lavandula spica L. (Lamiaceae). Taxon. 2001;50:1213–1214. [For nomenclature.]

Guinea E. Lavandula. In: Tutin et al., vol. 3. 1972:187–188.

McNaughton V. Lavender: the Grower’s Guide. Portland, OR: Timber Press; 2000.

Tucker AO. The correct name of lavandin and its cultivars (Labiatae). Baileya. 1981;21:131–133. [For nomenclature.]

Figure 37: a–b, Lavandula angustifolia flowers and calyx with large hairs not shown; c, L. latifolia.