Tulip classification
In the early 1900s the number of new tulip cultivars being introduced rose dramatically and, as a result, the Royal Horticultural Society set up an Anglo-Dutch committee to organise the naming and classification of tulips.
The first full classification system was published in 1939 and has been developed since then in collaboration with the Royal General Dutch Bulb Grower’s Society (the KAVB). The latest classification was published in 1987 and is as follows:
Early flowering
Div.1 Single early
Cup shaped, single flowers, often opening wide in the sun, from early to mid spring.
Div. 2 Double early
Long lasting double flowers which open wide, appearing early and mid spring.
Mid season flowering
Div. 3 Triumph
Sturdy stems with rather conical, single flowers opening to a more rounded shape, in mid and late spring.
Div. 4 Darwin hybrid
Large, single flowers of variable shape on strong stems from mid to late spring.
Late flowering
Div. 5 Single late
Single flowers, variable in shape but often ovoid or squarish, usually with pointed tepals. They appear in late spring and very early summer.
Div. 6 Lily-flowered
Strong stems with narrow-waisted, single flowers which have long, pointed tepals often reflexed at the tips, in late spring.
Div. 7 Fringed
Flowers are similar to those in div. 6 but have fringed tepals.
Div. 8 Viridiflora
Variably shaped, single flowers with partly greenish tepals are borne in late spring.
Div. 9 Rembrandt
A group consisting of mostly old cultivars which are similar to those in div. 6 but have colours ‘broken’ into striped or feathered patterns due to a viral infection. Flowers in late spring.
Div. 10 Parrot
Large, single flowers of variable shape with tepals frilled or fringed and usually twisted. Flowers appear in late spring.
Div. 11 Double late (peony-flowered)
Double flowers which are usually bowl-shaped and appear in late spring.
Species
Div. 12 Kaufmanniana
Single flowers which are usually bicoloured, open flat in the sun and come out in early spring. The leaves are often mottled or striped.
Div. 13 Fosteriana
Large, single flowers opening wide in the sun from early to mid spring. The leaves are often mottled or striped.
Div. 14 Greigii
Large, single flowers appear in mid and late spring. The leaves are generally wavy-edged and always mottled or striped.
Div. 15 Other species
A miscellaneous category of other species and their varieties and hybrids. Flowers can appear from spring through to early summer.