Rosa × damascena Mill. (derived from Rosa gallica L. and Rosa moschata Herm.), a member of the Rosa genus from Rosaceae family, has the common name of summer damask rose.
This species is a low, deciduous plant, with wide runners and is branched above ground. The length of the shoots of R. × damascena shrub is generally between 0.5 and 1.5 m and it is covered with tall, recurvate, or erect thorns and stem glands of various sizes. The leaves are usually divided into five, rarely seven, ovate to elliptic leaflets, and are long, glandular, grey–green above and are bluer below, leaflets grow together at the leaf stem and terminate in free tips (Figure 1).
Inflorescence is usually rather many-flowered, corymbiform, or corymbiform–paniculate. The flowers are usually solitary, more rarely in two and three, on 2–3 cm long thickly glandular pedicles, the calyx is round to pear-shaped and usually thickly covered with stalked gland and gland bristles. The velvety petals are pink to purple, 2–3 cm long and wide (Figure 2). The style and stigma form the ovary that is surrounded by carpels enclosed in the calyx, forming woolly capitula, the ripe and red-brown false fruit is oblong 1–1.5 cm long, and broadest in the upper part (Figure 3) (Brown, 2002; Fedorov et al., 1941; Khatamsaz, 1992).
Rosa × damascena is cultivated in Turkey, Iran, Bulgaria, and Morocco but it has also been cultivated in other areas of the world. A map of the main areas in which R. × damascena is cultivated is shown in Figure 4.
There are many reports concerning the composition of the essential oil of R. × damascena. Quercetin, kaempferol, cyanidin, lycopene, rubixanthin, zeaxanthin, xanthophyll, and taraxanthin have been isolated from the hips of the rose plant. The yield of the volatile oil is very low and it is about one part of oil from 3000 parts of flowers. However, the main constituents of the essential oil obtained from the flowers of this plant are citronellol, nerol, geraniol, β-phenylethanol, eugenol, and methyl eugenol (Khare, 2007). Due to the low oil yield from R. × damascena and also high demand for this volatile oil, it is one of the most expensive volatile oils (Alsemaan et al., 2011; Baydar and Baydar, 2005; Boskabady et al., 2011; Shahbazi and Esmaeili, 2012).
The constituents of the oil extracted from R. × damascena vary depending on the growing area. Iran, India, Bulgaria, China, and Turkey are the main countries that cultivate this shrub and produce the essential oil of this plant. The main components of the oil obtained from this plant cultivated in different parts of these countries summarized in Table 1.
Although the main compounds of the oil extracted in these countries are citronellol, geraniol, and nonadecane, there are also other compounds like docosane (up to 19%), disiloxane (up to 19%), and heneicosane (up to 18%) reported for Iranian oil. In addition, β-phenyl ethanol (50–86%) was reported for Turkish absolute and geranyl acetate plus citronellol (up to 25%) and heneicosane (up to 11%) was reported for “York and Lancaster” attar (Tucker and DeBaggio, 2009).