Ask a child to draw a tulip flower and a basic cuplike blossom appears on paper, perhaps made with a red crayon or marker. Native to western Asia, the first wild species of tulips encountered displayed bowl- to star-shaped flowers. After centuries of cultivation, genetic manipulation and selection for color, form and shape, modern tulip hybrids produce a wider array of flower shapes. Tulips may be single or double in form, based on the number of petals comprising each blossom.
While you may refer to them as petals, tulips more accurately flowers with six tepals. Tepals describe flower parts that aren’t easily distinguished as being petal or sepal. In other plant flowers, sepals typically cover a flower bud, remain green and support the bottom back of the flower petals. In tulips, it seems the sepals don’t exist. Examination of the tulip flower reveals six ambiguous tepals — perhaps described as three inner colored petals and three outer colored sepals.
A single cup tulip flower.
A huge number of modern tulip varieties produce single, cup-shaped blossoms. Single means six tepals in the flower that, when open, looks like a cup or the letter U. When developing, the flower bud remains tightly closed and tapers with a blunt point. Once open and warm weather allows the blossom to age and get pollinated by insects, the tulip flower maintains a U-like shape. Tepal edges can be smooth or fringed. Examples of tulip varieties with single, cup-shaped flowers include ‘Apricot Beauty,’ ‘Queen of the Night,’ ‘Golden Apeldoorn,’ ‘Negrita’ and ‘Pax.’ All tulips referred to as ‘Darwin’ or Triumph’ types usually bear single cups.
Bowl-shaped tulip tepals open slightly wider than cup-shaped flowers.
Tulips that produce flowers with multiple rows of tepals are referred to as double tulips. When open, the extra tepals make a fuller, almost peonylike blossom. When compared with a cup-shaped tulip, bowl-shaped flowers look much wider and tend to open more broadly. Petal edges can remain smooth and entire or have fringed edges. Varieties ‘Abba’, ‘Angelique,’ ‘Fringed Beauty,’ ‘Peach Blossom’ and ‘Carnaval de Nice’ develop bowl-shaped flowers across spring. Species Tulipa kaufmanniana and T. kolpakowskiana naturally produce single form, bowl-like blossoms.
The tepals of goblet or lily-flowering tulips flair out at the tips.
Goblet-shaped tulip flowers sometimes are described as lily-flowering. The three outer tepals are wide at their bases, curve inward and again flair out at their tips. Examples of lily-flowering tulips with goblet-shaped blooms include ‘Aladdin,’ ‘Green Star,’ ‘White Triumphator,’ ‘Ballade,’ ‘Mariette,’ ‘Maytime,’ ‘Queen of Sheba’ and ‘West Point.’
Star-shaped tulip blooms have not been genetically manipulated.
Many species tulips — those natural tulips that bloom nicely and have not been genetically manipulate by breeders — bear wide opening, star-shaped flowers. The three inner tepals often are a bit large while the three back or outer tepals are slightly narrower. Blossoms can start off looking cup- or bowl-shaped, but the wide, horizontal orientation when fully open makes a star-shaped designation obvious. Species with starry flowers include Tulipa biflora, T. humulis, T. clusiana, T. sylvestris, T. tarda and T. saxatilis.
Modern tulip breeders manipulate crosses for new, exotic flower color and form mutations. Among the mutations are tulips that bear flowers with tepals so reduced and slender that they look like tiny swords or blades of grass. The species Tulipa acuminata naturally bears extremely slender tepals that look like flickering candle flames, as does variety ‘Fireflame.’