This includes all roses developed since 1867 when the first Hybrid Tea was cultivated.
Species most important in the development of Modern cultivars were R. canina, R. chinenesis, R. foetida, R.gallica, R. gigantea, R. moschata, R. multiflora, R. phoenicia, R. rugosa, and R. wichuraiana.
Modern roses typically produce masses of flowers in a wide range of colours that last a long time and are repeat bloomers.
Tens of thousands of cultivars have been developed of which around 2000 are still available.
Gardening Australia’s 2000 edition of Flora illustrates nearly 1100 old and modern cultivars.
The oldest class of Modern garden roses they are crosses of the many flowered Hybrid Perpetuals and the tall Tea roses.
They grow as bushy shrubs or standards 1 to 2 m high.
Repeat-flowering, their long stems hold 1 large flower (up to around 10 cm across) and a few side buds that open slowly.
The tight buds and the semi-double or double flowers retain some or all of the conical features of the Tea rose.
The petal tips curl back and they come in a wide range of colours including yellow but not blue.
There are over 10,000 hybrids and some are common cut flowers.
Floribunda. The parents are Hybrid Tea and Polyantha roses.
Plants 30 to 120 cm high can be ground covers, stiff bushy shrubs, standards or climbers.
They have up to 25 semi or fully double flowers in large clusters (trusses).
Flowers have a typical Hybrid Tea shape but are smaller.
There are always some flowers on the plants.
Grandiflora roses, dating from 1952 are a cultivar of a Hybrid Tea and a Floribunda.
Plants have long erect canes up to 2.4 m high with many clusters of mostly double Hybrid Tea-shaped flowers.
They are repeat bloomers in yellow, red, pink, purple and white.
4. Other groups include:
Polyantha. With the parents R. multiflora and Hybrid Teas they are small compact shrubs to 60 (90) cm high with smaller leaves than Floribundas.
They have sprays of up to 15 single or double usually rosette type flowers only 2.5 cm across with flowers on the bush for months. Seldom seen now.
Climbing roses. With stems too weak to support the flowers they have to lean on or scramble over other vegetation or supports. They usually need to be trained to climb.
They are up to 6 m high with Hybrid Tea or Floribunda type flowers in a large range of colours.
Rambler roses are vigorous climbers or, if there is no support they will cover the ground.
They can grow to 8 m high and often have a lot of prickles that help them climb.
Many new shoots appear each year forming clumps of long canes. They often only flower once a year.
Tree or Standard Roses. These are any cultivar, but most often a Hybrid Tea, Floribunda or Grandiflora, grafted onto a high stem.
Miniature roses. Compact shrubs, mostly around 45 (15 to 90) cm high with dense foliage. They have very small leaves and tiny single to fully double flowers in clusters of up to 10 or 11 flowers. Flowers can be of various forms.
Ground cover roses. These shrubby (landscape) roses are low-growing but sprawling plants. Flowers can be singles or doubles.
Shrub Roses. A more recent group that holds all the roses that do not fit into the other groups.
(The HelpMeFind website has information on over 44,000 roses.)