About Lavandula stoechas L.
Lavandula stoechas L. is an evergreen shrub. It typically grows 30 to 100 centimetres (12 to 39 inches) tall; the subspecies L. stoechas subsp. luisieri occasionally reaches up to 2 metres (6.6 feet) tall. Its leaves are 1 to 4 cm long, greyish, and tomentose. The inflorescence is crowned by a mass of purple elongated ovoid bracts around 5 cm long. Lower flowers form a tight rectangle in cross-section. The uppermost of the five teeth bears an inverted heart-shaped appendage. The corolla is blackish-violet, up to 8 mm long, and forms an indistinct two-lipped shape. Flowers appear in late spring and early summer, ranging from pink to purple. They are produced on 2 cm long spikes at the top of slender, leafless stems that are 10 to 30 cm (4 to 12 in) long. Each flower is subtended by a bract 4 to 8 mm long. At the top of the spike sit several much larger, sterile bracts with no flowers between them; these bracts are 10 to 50 mm long, bright lavender purple, and rarely white. In its native habitat, blooming occurs from March onwards in spring and early summer, with timing varying based on the local climate. In cultivation, this species is more tender than common lavender (Lavandula angustifolia), with lower frost resistance. Its oils are harsher and more resinous than those of common lavender. Like other lavenders, it grows best in hot, dry, sunny conditions with alkaline soil, but it can tolerate a range of growing situations, though it may be short-lived. It is hardy down to −10 °C (14 °F), suitable for USDA zones 8–10. Three cultivars of this species have earned the Royal Horticultural Society's Award of Garden Merit: 'Ballerina', 'Pretty Polly', and 'Willow Vale'. For other uses, the flowers are used in aromatherapy to make infusions and essential oils, which contain the ketones d-camphor and d-fenchone, and the alcohols borneol and terpineol.
