Tulip (Tulipa)

Description

Tulipa (tulips) is a genus of spring-blooming perennial herbaceous bulbiferous geophytes, dying back after flowering to an underground storage bulb. Depending on the species, tulip plants can be between 4 inches (10 cm) and 28 inches (71 cm) high.Flowers: The tulip's flowers are usually large and are actinomorphic (radially symmetric) and hermaphrodite (contain both male (androecium) and female (gynoecium) characteristics), generally erect, or more rarely pendulous, and are arranged more usually as a single terminal flower, or when pluriflor as two to three (e.g. Tulipa turkestanica), but up to four, flowers on the end of a floriferous stem (scape), which is single arising from amongst the basal leaf rosette. In structure, the flower is generally cup or star shaped. As with other members of Liliaceae the perianth is undifferentiated (perigonium) and biseriate (two whorled), formed from six free (i.e. apotepalous) caducous tepals arranged into two separate whorls of three parts (trimerous) each. The two whorls represent three petals and three sepals, but are termed tepals because they are nearly identical. The tepals are usually petaloid (petal like), being brightly coloured, but each whorl may be different, or have different coloured blotches at their bases, forming darker colouration on the interior surface. Tulip flowers come in a wide variety of colours, except pure blue (several tulips with "blue" in the name have a faint violet hue), and have absent nectaries.Androecium: The flowers have six distinct, basifixed introrse stamens arranged in two whorls of three, which vary in length and may be glabrous or hairy. The filaments are shorter than the tepals, and dilated towards their base.Gynoecium: The style is short or absent and each stigma has three distinct lobes, and the ovaries are superior, with three chambers.Fruit: The tulip's fruit is a globose or ellipsoid capsule with a leathery covering and an ellipsoid to globe shape. Each capsule contains numerous flat, disc-shaped seeds in two rows per chamber.These light to dark brown seeds have very thin seed coats and endosperm that does not normally fill the entire seed.Leaves: Tulip stems have few leaves. Larger species tend to have multiple leaves. Plants typically have two to six leaves, some species up to 12. The tulip's leaf is cauline (born on a stem), strap-shaped, with a waxy coating, and the leaves are alternate (alternately arranged on the stem), diminishing in size as the further up the stem. These fleshy blades are often bluish-green in colour.The bulbs are truncated basally and elongated towards the apex, on the outside they are covered with a thin tunic, that is lined with hairs on the inside, but occasionally glabrous.Phytochemistry:Tulipanin is an anthocyanin found in tulips. It is the 3-rutinoside of delphinidin. The chemical compounds named tuliposides and tulipalins can also be found in tulips and are responsible for allergies.Tulipalin A, or α-methylene-γ-butyrolactone, is a common allergen, generated by hydrolysis of the glucoside tuliposide A. It induces a dermatitis that is mostly occupational and affects tulip bulb sorters and florists who cut the stems and leaves.Tulipanin A and B are toxic to horses, cats and dogs.