Iris species
There are more than 300 species of iris in the world, and more than 60 species in China, which are of great ornamental value. Iris can be divided into two types according to its underground stems:
Perennial root of iris tectorum
When you see that the underground part of iris is root-shaped, or rhizome-shaped, it is perennial iris. Iris perennialis is a perennial plant with sword-shaped leaves and erect flower stems. The most common are Iris germanica and Iris flavescens. The flowers of Iris germanica are blue, white and purple with rich colors. The yellow iris is yellow.
There is also a kind of perennial iris. Because of the arrival of winter, when most varieties wither, the aboveground parts will remain green, so it is called evergreen iris.
Iris bulb
When you see that the underground part of iris is bulbous, it is bulbous iris. Iris bulbifera likes warmth and can promote greenhouse cultivation. Including Dutch iris, Denver iris, reticulated iris, etc., the colors are blue, purple and white.
Iris bulbifera is propagated by planting bulbs. One kind has been planted for a year, but it decays after flowering. After new bulbs are produced, the first born bulbs will bloom again after reproduction.