Dedicated to America’s favorite flower: the Rose!

Basic Rose Terminology

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.
  • Stipule – A leaf appendage that is usually present in roses on the petiole where it meets the stem.
  • Style – The part of the pistil that connects the ovary and the stigma.
  • Terminal – A term applied to buds occurring at the end of branches. The end or tip.
  • Thorn – A branch of a plant that becomes woody, hard and pointed. Cactus plants have thorns, locust trees have thorns. Rose do NOT have thorns as the ‘prickles’ on a rose do not develop from ‘branch’ tissue.
  • Trunk – The main stem of a rose, the cane that later produces all the side branches or lateral canes.
  • Vegetative Bud – A bud that produces only leaves and never flowers. Roses do NOT have vegetative buds.

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