stylistic:style_transfer
Bearded rhizome iris

Bearded iris are classified as dwarf, tall, or aril. In Europe, the most commonly found garden iris is a hybrid iris (falsely called German iris, I. germanica which is sterile) and its numerous cultivars. Various wild forms (including Iris aphylla) and naturally occurring hybrids of the Sweet iris (I. pallida) and the Hungarian iris (I. variegata) form the basis of almost all modern hybrid bearded irises. Median forms of bearded iris (intermediate bearded, or IB; miniature tall bearded, or MTB; etc.) are derived from crosses between tall and dwarf species like Iris pumila.

The "beard", short hairs arranged to look like a long furry caterpillar, is found toward the back of the lower petals and its purpose is to guide pollinating insects toward the reproductive parts of the plant. Bearded irises have been cultivated to have much larger blooms than historically; the flowers are now twice the size of those a hundred years ago. Ruffles were introduced in the 1960s to help stabilize the larger petals.

Bearded iris are easy to cultivate and propagate and have become very popular in gardens. A small selection is usually held by garden centres at appropriate times during the season, but there are thousands of cultivars available from specialist suppliers (more than 30,000 cultivars of tall bearded iris). They are best planted as bare root plants in late summer, in a sunny open position with the rhizome visible on the surface of the soil and facing the sun. They should be divided in summer every two or three years, when the clumps become congested.

A truly red bearded iris, like a truly blue rose, remains an unattained goal despite frequent hybridizing and selection. There are species and selections, most notably based on the beardless rhizomatous Copper iris (I. fulva), which have a relatively pure red color. However, getting this color into a modern bearded iris breed has proven very difficult, and thus, the vast majority of irises are in the purple and blue range of the color spectrum, with yellow, pink, orange and white breeds also available. Irises – like many related genera – lack red-based hues because their anthocyanins are delphinidin -derived. Pelargonidin -derived anthocyanins would lend the sought-after blue-based colors but these genera are metabolically disinclined to produce pelargonidin. Dihydroflavonol 4-reductases in Iris ' s relatives selectively do not catalyse dihydrokaempferol to leucopelargonidin, the precursor, and this is probably the case here as well. The other metabolic difficulty is the presence of flavonoid 3'-hydroxylase, which in Chrysanthemum inhibits pelargonidin synthesis. The bias in irises towards delphinidin-anthocyanins is so pronounced that they have served as the gene donors for transgenic attempts at the aforementioned blue roses. Although these have been technically successful – over 99% of their anthocyanins are blue – their growth is crippled and they have never been commercializable.