Arching habit When a rose’s stems arch outwards, fountain-style.

Attar of roses The intoxicating scent of ‘attar of roses’ has worked its magic on us for millennia. Extracted by steam distillation from the petals of fragrant roses like the Damask and Centifolia, the attar is concentrated rose essential oil. Most of the world’s attar of roses is produced in Bulgaria. It takes 30,000 rose petals to produce just one ounce of attar and this ounce costs between $100-200 US dollars to buy in the United States. Attar may also be called ‘rose essence’, ‘Otto of roses’ or ‘oil of roses’.

Balling When a rose’s bloom fails to open after rain or damp weather. Susceptible roses are those with many petals like Centifolias.  What happens is that the outer petals of the bud become waterlogged and congeal around the inner petals preventing the bud from opening. Sometimes if the outer petals of an affected rosebud are carefully loosened, the bud will still have a chance to open.

Bareroot Most common way of buying roses in winter. The roses are lifted from the ground when they are dormant, freed of soil and sold as ‘bareroot’

Basal Cane A primary cane originating at the base of the plant.

Bicolor Term used to describe a rose flower with two clearly defined colours, one on the upper surface of the petal and the other on the underside (reverse) of the petal.

Blackspot  A fugal disease. It thrives in humid weather and is characterised by black spots that appear on a rose’s foliage.

Blend A rose flower with two or more colours blending together on each of its petals.

Blind shoot Stems that produce no flower are described as ‘blind’

Briar Roses Roses of the Dog Rose family (R. canina) including the Sweet Briar
(R. rubiginosa/R. eglanteria) and Austrian Briar (R. foetida). Often used more loosely for any Wild Rose.

Bud A rose flower is described as a ‘bud’ when it is anywhere between being fully-closed to half-open.

Bud Union Only found on grafted plants, the ‘bud union’ is the swollen junction at the base of the rose plant where the rootstock (understock) meets the rose plant above.

Calyx This is the protective cover that encloses the rosebud. As a rose flower opens the calyx splits into five sepals.

Cane The name given to a long, often flexible woody stem.

Cupped Used when referring to the shape of a flower when it is rounded and full, like a tea cup. 

Crenate Refers to the way the margins of a leaf look. If the edge is scalloped it is called ‘crenate’.

Corymb When a cluster of flowers forms a flattish topped arrangement at the end of the stem, it is said to be a ‘corymb’.

Cultivar Short for ‘cultivated variety’. Used to describe plants that have originated in a garden rather than those taken directly from the wild. Is used interchangeably with the word ‘variety’ in rose books.

Deadheading The gardening practice of removing spent flowers to encourage more flowers to grow. The best method is to cut the spent rose flower off at the flower stalk, just below the flower. In the past the stem was cut further down but current research suggests that just a light trim produces better results.

Dentate Refers to the way the margins of a leaf look. If the edge is composed of angular teeth at right-angles to the margin (and not angled forward towards the tip) then it is ‘dentate’. If they are angled forward it is ‘serrate’.

Double Refers to the number of petals a rose flower possesses. ‘Double’ flowers have many petals and when the number exceeds 40, like the Cabbage Rose, it’s described as being ‘very double’. According to the Royal National Rose Society, there are actually seven degrees of fullness when describing a rose:

    Single 4-7 petals
    Semi-double 8-14 petals
    Not full 15-19 petals
    Moderately full 20-24 petals
    Fairly full 25-29 petals
    Full 30-40 petals
    Very full Over 40 petals
You will find that most rose books use these terms more flexibly, depending on the writer.

Flore Pleno ‘Double’ ‘Flower’

Floriferous Free-flowering.

Glabrous  A surface (like a leaf) that is free of hairs.

Glaucous This term is used to describe a rose’s foliage when it is a greyish blue-green colour as in R. glauca

Grafted A method of propagating roses where the bud of the desired rose is grafted onto the roots of another rose known as the ‘rootstock’. The advantages of grafting a plant is the ease of propagation and the increased vigour of the grafted plant. The disadvantages are a plant that is more vulnerable to damage during cold weather and a plant that over time can have a shorter life-expectancy.  Whether a rose will grow better on its ‘own roots’ or as a ‘grafted’ plant depends on the individual rose.

Genus Roses belong to the genus 'Rosa.' A genus is a botanical way of organising together all plants which have characteristics in common. Often you will see the genus abbreviated in a botanical name. For example, Rosa centifolia is abbreviated to R. centifolia.

Hip The rose’s ‘hip’ is the vessel in which the rose’s seeds form and mature. It can be round or oval shaped and appears in the autumn (fall). The Old Roses or Species Roses usually have the most dramatic hips. For example, R. rugosa has hips as round and red as small tomatoes. Rosehips are edible and can be made into syrup, jam, chutney and wine. They are one of the richest natural sources of vitamin C.

Hispid A surface (like a leaf) covered with stiff coarse hairs.

Hybrid In respect to roses, a ‘hybrid’ is the plant that results from breeding together two different rose species. This may happen naturally or with human intervention. The parents of hybrids are selected by the rose breeder in the hope of combining desirable qualities from each parent in the hybrid. Hybrids are often more vigorous than their parents, a quality known as ‘hybrid vigour’. Hybrids may be sterile or it may not be possible to reproduce a hybrid identically from its own seed.

Lateral cane These are the branches that originate from the ‘basal cane’ When plentiful they create a shrub with a bushy appearance.

Layering A method of propagation. Roses with long flexible shoots can be layered by bending the cane down to ground level, pegging it in place and covering the pegged portion of the shoot with soil. Over time the shoot will put down roots. It can then be removed from the parent plant and planted elsewhere.

Leaflet Leaf-like sections arranged in a group along a common leaf stalk. They are collectively called a ‘compound leaf’.

Mildew See ‘Powdery Mildew’

Obovate Refers to the shape of a leaf, meaning ‘broadest in the upper half’

Once-flowering A rose that flowers only once during its growing season. Once-flowering roses make up for their lack of flowering during the rest of the year by putting all their energy into one profuse flowering usually in the spring or summer. The display may last from two weeks to two months. 

Ovate Refers to the shape of a leaf, meaning ‘broadest in the lower half’

Own-root A plant growing on its own roots as opposed to a plant that has been grafted onto the roots of another. See also ‘grafted’.

Pegging down A method of growing roses where the long shoots are bent to the ground and fixed with wooden pegs. Usually only applied to old rose varieties with long, flexible canes, it encourages the shoots to flower along the whole length, rather than just at the ends.

Pinnate Composed of more than three leaflets arranged in two rows along a common stalk.

Pistil The female part of the flower including the ovary, style and stigma.

Powdery Mildew  A fugal disease that covers a rose’s foliage with a white powdery substance and makes the leaves distort and curl. The mildew penetrates the leaf and feeds off the plant. For those who don’t like using chemical sprays, it can be controlled by spraying the foliage with a baking soda solution.

Reverse. Underside of the petal.

Receptacle The thickened tip of the flower stalk.

Reflexed/Reflexive When the petals turn or curl back at the edges.

Remontant From the French meaning to ‘rise again’. As applied to roses it means those that flower more than once during the growing season. Usually the term ‘repeat flowering’ is used instead. Many Old Roses are once-flowering but those that are ‘remortant’ may bloom in successive waves like the Chinas or may have two distinct blooming periods; one in spring and one in autumn (fall) like the ‘Four Seasons Damask’ rose.

Revert When a ‘sport’ returns to its original state.

Rootstock Used when describing grafted plants. The ‘rootstock’ is the rose plant that supplies the roots in a grafted plant.

Scion As distinguished from a ‘cutting’, a ‘scion’ is a detached shoot and its leaf-buds that will be inserted in ‘rootstock’ to produce a grafted plant.

Semi-double Refers to the number of petals a flower possesses – the centre of the flower should be semi-visible. See also the entry ‘Double’

Sepal See ‘Calyx’

Serrate Refers to the way the margins of a leaf look. If the little jagged edges point towards the tip of the leaf it is called ‘serrate’.

Single Refers to the number of petals a flower possesses – usually between 4-8. The centre of the flower should be completely visible. See also the entry ‘Double’

Species Rose Also known as ‘Wild Roses’, ‘Species Roses’ are those which have evolved in the wild and when self-pollinated, will ‘come true’. That is, they will have the same characteristics as their parent when grown from self-pollinated seed.

Sport A spontaneous development on a plant that is different to the rest of the plant – usually the result of a ‘mistake’ occurring in the DNA during cell division. This can be desirable – for example it may produce a new flower colour or leaf shape. However, as the plant continues to grow, the ‘mistake’ may be corrected. When this happens the ‘sport’ is said to ‘revert’, that is, return back to its original form. Some sports are more stable than others. They can be propagated by grafting but not by seed. Redouté and Thory talk a lot about the phenomena of ‘sports’, especially when describing the Centifolia Roses. At the time no one knew what caused a plant to ‘sport’.

Stamen The male part of the flower that carries the anther. The anther releases pollen.

Stipules The leaf-like attachments at the base of a leaf stalk. Can be comb-like, fringed, toothed or slashed. They are called ‘adnate’ when they grow along the length of the leaf stalk.

Sucker An unwanted shoot growing from the rootstock of a grafted rose plant. If the sucker is not removed it will gradually take over and the grafted plant will be lost.

Thorns The prickly, sharp growths on rose stems. To be botanically correct, rose thorns should be called ‘prickles’ because they are not true thorns. However, I don’t imagine anyone who’s just tackled pruning a well-armoured rose will feel in the mood to call them mere ‘prickles’!

Tomentose A surface (like a leaf) that has a thick covering of short hairs.

Umbels When the flower stalks rise up like umbrella spokes from the top of the main stem.

Understock See ‘Rootstock’