By: Jolene Adams, jolene_adams[at]comcast[dot]com, Consulting Rosarian

When speaking about roses it makes it much easier if all of us use the same terminology. The following is a list of basic terms used to describe rose plant parts. It is a lot easier to understand what someone is talking about when they say “sepals” rather than “… you know, those little green things just under the flower …”

• Anther – The upper portion of a stamen which contains the pollen sacs.

• Apical Meristem – Non-maturing cells located at the tips of shoots and roots which produce the plant hormone auxin.

• Auricle – The ‘ear-like’ projection found on the tip of the stipule.

• Auxin – a plant hormone that regulates the bloom cycle for rose buds.

• Axil – the angle on the upper side where the leaf and stem join.

• Axillary – A term applied to buds or branches occurring in the axil of a leaf. These buds begin to grow after pruning or deadheading.

• Bark – The outer layer of the stem of a rose.

• Bud – An embryonic shoot that may eventually produce either flowers of foliage.

• Bud Union – That area between the roots and the stems where the bud of the desired variety was grafted onto the rootstock.

• Bract – A leaf unlike the ordinary leaves which is usually smaller or of a different shape, growing from the peduncle just below the flower.

• Calyx – The first of a series of flower parts growing from the peduncle, composed of sepals, usually green and leaf-like.

• Cane – The stem of a rose, either the main stem (which then becomes the trunk) or lateral stems or branches.

• Carpel – An organ bearing ovules along its margins; part of a compound pistil.

• Compound Leaf – A leaf composed of two or more parts or leaflets. Rose leaves are pinnately compound.

• Corolla – The second of a series of flower parts growing from the peduncle, composed of petals.

• Double – Referring to how many petals the rose has – usually between 25 and 45.

• Filament – The stalk of the stamen which supports the anther.

• Floral Tube – A cup-like structure formed by the fusion of the basal parts of the sepals, petals and stamens. Don’t call it a ‘calyx tube.’

• Fruit – A ripe ovary containing seeds and any adjacent parts.

• Hip – The fruit of the rose which contains the seeds.

• Leaf – An organ arising laterally from superficial tissues of a shoot apex. It is usually flat and may be simple or compound.

• Leaf Scar – A mark left on the stem where the leaf detaches. There is a bud just above each leaf scar.

• Meristem – Tissue composed of cells that do not mature, but remain capable of further growth and division. Present in growing tips.

• Mixed Buds – Buds that produce both leaves and flowers; usual type of bud on roses; present in leaf axils.

• Ovary – The swollen basal portion of the pistil containing the ovules or seeds.

• Ovule – A structure containing the embryo sac, nucellus, integuments and stalk. After fertilization this develops into seeds.

• Peduncle – The main stem of a an individual flower or of a spray.

• Pedicel – The stem of an individual flower in a spray.

• Perianth – The collective term for the calyx and corolla (sepals and petals) combined.

• Petal – One of the units of the corolla of the flower. Roses have from four to over 100 petals, depending on the variety.

• Petaloid – A transitional phase between petals and stamens.  Petalloids are visible in single and semi-double roses as deformed-looking petals in the center of the rose.

• Petiole – The stalk of the leaf.

• Petiolul – A subdivision of the petiole which connects the lateral leaflets to the petiole.

• Pistil – The central organ of the flower composed of one or more carpels and enclosing the ovules.

• Pith – The soft inner portion of a rose stem.

• Pollen – The granules within the pollen sacs containing genetic information used for sexual reproduction.

• Prickle – A spine-like superficial outgrowth of the stem. Roses have prickles, not ‘thorns.’

• Roots – The underground parts of the rose used for support and to absorb water and nutrients.

• Rootstock – The cultivated roots of a rose which will be implanted with a bud from another variety (grafting).

• Semi-double – Referring to how many petals the rose has – usually 12 to 25.

• Sepal – One of the units of the calyx. These are the green coverings of a flower bud that open to reveal the petals of the rose. Roses usually have 5 sepals.

• Single – Referring to how many petals the rose has – usually four to eight.

• Spray – Several flowers buds which arise from one peduncle and develop into many flowers on short pedicels.

• Stamen – The organ of the flower producing pollen, composed of an anther and a filament.

• Stigma – The top of the pistil, the part that receives the pollen grains.