The most common "true" species in cultivation is the common or English lavender Lavandula angustifolia (formerly L. officinalis). A wide range of cultivars can be found. Other commonly grown ornamental species are L. stoechas, (Spanish lavender) L. dentata (French lavender), and L. multifida (Egyptian lavender). Some species such as Lavandula stoechas are not winter hardy in temperate climates - USDA Zones 8-10). 
The lavandins Lavandula × intermedia are a class of hybrids of L. angustifolia and L. latifolia. The lavandins are widely cultivated for commercial use, since their flowers tend to be bigger than those of English lavender and the plants tend to be easier to harvest, but lavandin oil is regarded by some to be of a lower quality than that of English lavender, with a perfume less sweet.