Rose leaves are usually five to fifteen centimetres long, have a serrated margin and have a few small prickles on the underside. The stem also has prickles – these are commonly mistaken for thorns, but they are sickle-shaped and are designed to help the plant hang onto other vegetation, and prevent animals browsing.
The petals of a rose are modified leaves that are given extra nutrients to take on different colours and fragrances. They are designed this way to attract bees and birds for
Anatomy of a Rose
pollination. Before the rose matures or blooms, the petals are protected from the sun, wind and rain by sepals. As the flower opens, the sepals spread apart and open with the flower, alternating between each rounded petal. The sepals are typically green and there are five in number (like the amount of petals a rose has – apart from the Rosa Sericea, which has four).
The rose is asexual because it has both male and female parts. The male parts (the stamen, anthers and filaments) produce the pollen grains. With the aid of pollinators, these fertilise the female parts of the rose (the stigma, styles and ovary).
Below the petals and sepals is where the ovary sits. Unlike many other flower species, the rose contains several ovaries and ovules within a fruit called a ‘hip’, the bulbous base of the rose bud. The hips of most species are red, but a few such as the Rosa Pimpinellifolia have dark purple to black hips. Each hip has an outer fleshy layer, the hypanthium, which contains up to 160 seeds. These seeds are embedded in a matrix of fine but stiff hairs, which then get dispersed by birds in their droppings. Rose hips are also edible to people and are rich in vitamin C.
At the centre of the rose you will find the stigma and the stamen. Unlike many other flowers, the rose has several. This is where the flower gets pollinated by bees and birds. Anthers sit on top of filaments and are the organs at the upper end of a stamen that produce the pollen. The stigma is where the pollen is applied from the stamen – when it is ready to receive the pollen, it exudes a clear sticky fluid. After the pollen is germinated, it travels down one of the many tubes called styles to the ovary. The stamens and stigmas come in a variety of colours and the texture of the stigma is like a cauliflower.
Rose breeders use their knowledge of the parts of the rose to help produce new varieties. They collect pollen from one type of rose and pollinate it with a different type. The pollinated ovary grows into a rose hip and the seeds can be extracted, dried and planted to see what grows. However, this type of cross-breeding can create roses so tightly petalled that natural pollination then cannot occur.
Find out about the history of Red Roses, White Roses, Pink Roses and Yellow Roses
