Daylilies arrived in the United States from England in the 17th century and quickly adapted to the new environment. The Chinese have been using this hardy plant as medicine, food and decoration for 2,500 years.

If you're a daylily junkie, you'll be glad to know that there are 60,000 registered cultivars, and since daylilies are easy to hybridize, about 500 new varieties are added each year.

You'll definitely run out of space before you run out of different daylilies. The genus name is Hemerocallis (hem-er-oh-CAL-iss), which comes from the Greek words for "day" and "beautiful." As the name implies, the daylily flower blooms for only one day. This would be a drawback if only one bud was on each plant, but daylilies have enough buds to keep a plant blooming for up to a month.

Where did daylilies come from? In China, they have been used for 2,500 years for medicine, food, and for their ornamental value. The flowers, flower buds and young leaves were eaten as vegetables and the roots and leaves were used as a pain reliever and for other medicinal purposes. A bowl of daylily soup can be had in many Chinese restaurants.

Daylilies first showed up in Europe in the mid-sixteenth century. History of the plant shows that the lemon daylily arrived first in Hungary via Mongolia and the familiar roadside daylily that we see growing everywhere was brought to Venice by Arabian traders and to Lisbon by Portuguese merchants.

They arrived in the United States from England in the 17th century and quickly naturalized. Another name for the Tawny Daylily (roadside variety) was the Outhouse Lily because it was frequently planted around outhouses.

Only a few daylilies have a scent, but their variety, hardiness, and ability to grow in almost any kind of soil overrides the lack of scent.

Daylilies are hardy in Zones 1 through 11 (remember, we're in Zone 5 so we are definitely OK with this plant). They like full sun but will grow in partial shade also. Daylilies are available in pink, yellow, orange, red, purple, lavender, greenish tones, near-black, near-white; a blue daylily has not yet been developed, but hybridizers are working on this.

Daylily flowers are composed of three broad petals and three narrow, petal-like sepals that overlap for a portion of their length. Tepals is the combined name for the two parts. Each has a mid-rib with the same color as the petal or a contrasting color. The center of the flower is called a "throat" and usually has a contrasting color. The plant itself grows as a clump with long, lance-like leaves that are grouped into opposite flat fans. The leaves arch out from both sides of the plant. The flowers grow on scapes which are leafless flowering stems.

Daylilies are categorized in several different ways — by evergreen, semi-evergreen and dormant. In Western Pennsylvania, the daylily foliage dies back in winter and thus our plants are dormant.

Another classification is height: dwarf (below 6 inches), low (1 to 2 feet tall), medium (2 to 3 feet tall), and tall (over 3 feet).

Daylilies can also be "tetraploid" plants or "diploids." Tetraploid's have thicker petal substance and sturdier stems and offer larger flowers. The thick petals enable them to resist heat and keep their color. At this time, only one daylily ('Kwanso') is known as a "triploid," which produces three times the usual number of petals. Blooms on this daylily are 5 to 6½ inches across and are tangerine.

Hybridizers are always looking for new varieties by creating broad petals, bicolor bands and blazes, extra frills, extended bloom and scent. In doing this, however, some of the grace of the species and older cultivars has been lost. Many older plants are seldom available and risk being displaced.

You might want to consider adding a few of these lovely and useful species daylilies such as the lemon daylily. Reblooming daylilies are available but mainly these plants rebloom only in the southern part of the country. This is another area where hybridizers may one day make inroads, and we could see reblooming daylilies here. It is possible that you may get re-blooms with a plant such as 'Stella 'd Oro', 'Happy Returns,' or "Rosy Returns'.

Awards for daylilies are presented by the American Hemerocallis Society, which recognizes those plants that have performed well in gardens around the country. The AHS symbol signifies an award-winning daylily that has distinguished itself in the eyes of the garden judges. You can visit on the AHS Web site at www.daylilies.org, where you will find a wealth of information on daylilies.

Look for information on planting, caring for, and dividing daylilies in the next article.

Maryellen Walter is a Master Gardener with the Penn State Master Gardener program. She lives in Butler County.