Lavender, belonging to the genus Lavandula, is a highly recognizable flowering herb celebrated for its distinctive aroma and aesthetic appeal. It is a staple in gardens worldwide, often used in aromatherapy and culinary applications. Identification is important, whether for harvesting its fragrant flowers or appreciating it in a landscape. Learning to differentiate it by its physical structure and unique volatile oil profile allows for confident identification.
Identifying Features: Sight and Scent
Lavender plants possess a semi-woody, shrub-like structure that typically features a compact, mounding growth habit. The stems rising from the woody base are often square or four-sided, characteristic of the mint family, Lamiaceae. The foliage is narrow, linear, and covered in fine, star-shaped hairs called trichomes. These trichomes give the leaves a distinct silvery-green or gray appearance.
The tiny, fragrant flowers are arranged in dense clusters or whorls that form terminal spikes at the top of long, upright stems. Flower colors range from the expected bluish-purple and violet to pink or white, depending on the specific variety. The powerful scent is the most reliable identifier, stemming from oil glands embedded among the trichomes on the flowers and leaves.
The aroma is primarily composed of the monoterpenoids linalool and linalyl acetate. Linalool contributes a sweet, floral, and slightly woody quality, while linalyl acetate enhances the soft floral sweetness. Crushing a leaf or flower releases these oils, providing an instant, unmistakable smell test. This test is the definitive proof of true lavender.
Common Types and Their Differences
The genus Lavandula is diverse, with several species commonly cultivated, each possessing distinct characteristics. Lavandula angustifolia, known as English Lavender, is prized for its sweet, low-camphor scent and its compact size, making it the preferred variety for culinary use. Its leaves are typically narrow and smooth-edged, and the flower spikes are short and plump.
Spanish Lavender, Lavandula stoechas, is easily identified by a unique visual trait: showy, petal-like bracts that resemble “bunny ears” or flags sitting atop its dense flower spikes. This species often has a resinous, pine-like fragrance due to higher levels of compounds like fenchone, giving it a less sweet and more medicinal aroma.
French Lavender, Lavandula dentata, is recognizable by its foliage, as its name refers to the toothed or fringed leaf margins. This plant often has a slightly camphorous, herbaceous scent and performs well in warmer climates, blooming almost continuously in mild conditions.
Lavandin, Lavandula x intermedia, is a robust hybrid of English and Portuguese lavender, grown commercially for its high essential oil yield. These plants are significantly larger than English lavender, featuring much longer flower stems and a strong, pungent aroma with a noticeable camphor content.
Distinguishing Lavender from Look-Alikes
Several garden plants share the silvery foliage and purple flower spikes of lavender, leading to frequent misidentification. Russian Sage, Perovskia atriplicifolia, is often confused with lavender due to its gray-green leaves and violet-blue flowers. However, Russian Sage grows taller with a more airy, branching habit. When crushed, its leaves emit a pungent, menthol-like scent rather than the sweet floral aroma of true lavender.
Catmint, Nepeta, is another common look-alike featuring purple flower spikes and a soft, mounding growth habit. Unlike lavender, which has a woody base and narrow leaves, catmint has a more herbaceous growth pattern with rounder, softer leaves. Its aroma profile is often described as lemon-minty. Catmint is also much more tolerant of heavy or wet soil, whereas lavender requires sharp drainage.
Hyssop, Hyssopus officinalis, is a shrubby herb that also produces blue flower spikes. It can be differentiated from lavender by its leaves, which are generally greener and broader than the silvery, narrow foliage of Lavandula. The scent of hyssop also contains an aniseed or licorice undertone, distinguishing it from the classic sweet or camphorous notes of the various lavender species.