Daylily

Daylily
Hemerocallis 'Hush Little Baby'
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Asparagales
Family:	Asphodelaceae
Subfamily:	Hemerocallidoideae
Genus:	Hemerocallis
Species
See text.

Daylily is the general nonscientific name of a species, hybrid or cultivar of the genus Hemerocallis (/ˌhɛmroʊˈkælɪs/). Daylily cultivar flowers are highly diverse in colour and form, as a result of hybridization efforts of gardening enthusiasts and professional horticulturalists. Thousands of registered cultivars are appreciated and studied by local and international Hemerocallis societies. Hemerocallis is now placed in family Xanthorrhoeaceae, subfamily Hemerocallidoideae, and formerly was part of Liliaceae (which includes true lilies).

"The Perfect Perennial"

The daylily is often called "the perfect perennial," due to its dazzlings colors, ability to tolerate drought, capability to thrive in many zones, and requiring very little care. Daylilies thrive in full sun, although certain daylilies require partial shade, depending on color. Lighter shades, such as yellow, pink, and pastels require the sun to bring out all of their color. Darker daylilies, such as some red and purple flowers, need shade because their darker colors absorb heat.

Today, daylilies come in an assortment of shades, whereas they formerly were only available in yellow, pink, fulvous, and rosy-fulvous. Now the flowers can be found in many shades of yellow, pink, red, purple, and melon. The only shades daylilies are not available in are pure blue and pure white, which hybridizers are working on.

Daylilies have a relatively short blooming period, depending on the type of daylily. There are a variety of different dayliles; some of which will bloom in early spring, while other wait until the summer or even fall. Most dayliles bloom for one to five weeks, although there is a type of daylily known as a rebloomer, which will bloom twice in one season.

Cultivars

Hemerocallis 'Kwanzo' – a triple-flowered triploid cultivar

Depending on the species and cultivar, daylilies grow in USDA plant hardiness zones 1 through 11, making daylilies some of the more adaptable landscape plants. Hybridizers have developed the vast majority of cultivars within the last 100 years. The large-flowered, bright yellow Hemerocallis 'Hyperion', introduced in the 1920s, heralded a return to gardens of the once-dismissed daylily, and is still widely available in the nursery trade. Daylily breeding has been a specialty in the United States, where daylily heat- and drought-resistance made them garden standbys since the 1950s. New cultivars have sold for thousands of dollars, but sturdy and prolific introductions sell at reasonable prices of US$20 or less.

The Tawny Daylily (Hemerocallis fulva), and the sweet-scented Lemon-lily (H. lilioasphodelus; H. flava, old name) were early imports from England to 17th-century American gardens and soon escaped from gardens. The introduced Tawny Daylily is now common in many natural areas, and some people think that it is a native wildflower. Its nonscientific names include Railroad Daylily and Roadside Daylily, Ditch Lily, and Outhouse Lily, Tiger Lily, and Wash-house Lily (although it is not a true lily). Some people have planted this species near outhouses and wash houses, hence two of its nonscientific names.

Hemerocallis is one of the very highly hybridized plant genera. Hybridizers register hundreds of new cultivars yearly. Hybridizers have extended the genus' color range from the yellow, orange, and pale pink of the species, to vibrant reds, purples, lavenders, greenish tones, near-black, near-white, and more. However, hybridizers have not yet been able to produce a daylily with primarily blue flowers in forms of blue such as azure blue, cobalt blue, and sky blue. Flowers of some cultivars have small areas of cobalt blue.

The Tawny Daylily (Hemerocallis fulva)

Other flower traits that hybridizers developed include height, scent, ruffled edges, contrasting "eyes" in the center of a bloom, and an illusion of glitter which is called "diamond dust." Sought-after improvements include foliage color and variegation and plant disease resistance and the ability to form large, neat clumps. Hybridizers also seek to make less-hardy plants hardier in Canada and the Northern United States by crossing evergreen and semi-evergreen plants with those that become dormant and by using other methods. Many kinds of daylilies form clumps of crowded shoots. People dig up such kinds every 3 or so years, separate shoots, and replant only some of the shoots to reduce crowding. This process increases the flowering of many cultivars.

In the last several decades, many hybridizers have focused on breeding tetraploid plants, which tend to have sturdier scapes and tepals than diploids and some flower-color traits that are not found in diploids. Until this trend took root, nearly all daylilies were diploid. "Tets," as they are called by aficionados, have 44 chromosomes, while triploids have 33 chromosomes and diploids have 22 chromosomes per individual plant. Hemerocallis fulva 'Europa', H. fulva 'Kwanso', H. fulva 'Kwanso Variegata', H. fulva 'Kwanso Kaempfer', H. fulva var. maculata, H. fulva var. angustifolia, and H. fulva 'Flore Pleno' are all triplods that almost never produce seeds and reproduce almost solely by underground runners (stolons) and dividing groups by gardeners. A polymerous daylily flower is one with more than three sepals and more than three petals. Although some people synonymize “polymerous” with “double,” some polymerous flowers have over five times the normal number of petals.

The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-

'Beloved returns'	'Green flutter	'Red precious'
'Berlin lemon'	'Helle Berlinerin'	'Royal Mountie'
'Berlin red'	'Lemon bells'	'Stoke Poges'
'Berlin red velvet'	H. lilioasphodelus	'Tetrina's Daughter'
'Burning daylight'	'Marion Vaughn'	'Whichford'
'Cartwheels'	'Missenden'
'Chief Sarcoxie'	'Neyron rose'
'Corky'	'Nova'
'Golden chimes'	'Pink damask'

Culinary use

Dried golden needles

The flowers of some species are edible and are used in Chinese cuisine. They are sold (fresh or dried) in Asian markets as gum jum or golden needles (金针 in Chinese; pinyin: jīnzhēn) or yellow flower vegetables (黃花菜 in Chinese; pinyin: huánghuācài). They are used in hot and sour soup, daylily soup (金針花湯), Buddha's delight, and moo shu pork. The young green leaves and the rhizomes of some (but not all) species are also edible. The plant has also been used for medicinal purposes. Care must be used as some species of lilies can be toxic.

Species

Hemerocallis fulva, illustration of 1885

Hemerocallis thunbergii

'Red Magic' – a daylily cultivar

A Hemerocallis lilioasphodelus cultivar growing in Venezuela

The World Checklist of Selected Plant Families recognizes 18 species as of February 2012:

• Hemerocallis citrina Baroni (syn. H. altissima Stout, H. coreana Nakai)
• Hemerocallis darrowiana S.Y.Hu
• Hemerocallis dumortieri E.Morren
• Hemerocallis esculenta Koidz. (syn. H. pedicellata Nakai)
• Hemerocallis forrestii Diels
• Hemerocallis fulva (L.) L. (H. sempervirens Araki, H. sendaica Ohwi and H. aurantiaca Baker are now treated as varieties of this species) – Orange Daylily, Tawny Daylily, Tiger Lily, Ditch Lily
• Hemerocallis hakuunensis Nakai (syn. H. micrantha Nakai)
• Hemerocallis hongdoensis M.G.Chung & S.S.Kang
• Hemerocallis lilioasphodelus L. (syn. H. flava (L.) L.) – Lemon Lily, Yellow Daylily
• Hemerocallis littorea Makino
• Hemerocallis middendorffii Trautv. & C.A.Mey. (includes H. exaltata Stout as H. m. var. exaltata)
• Hemerocallis minor Mill. (syn. H. sulphurea Nakai)
• Hemerocallis multiflora Stout
• Hemerocallis plicata Stapf
• Hemerocallis taeanensis S.S.Kang & M.G.Chung
• Hemerocallis thunbergii Barr (syn. H. serotina Focke, H. vespertina Hara)
• Hemerocallis yezoensis H.Hara
• Hemerocallis nana W.W.Sm. & Forrest

Two hybrids are recognized:

• Hemerocallis ×exilis|Hemerocallis ×exilis Satake = H. fulva var. angustifolia × H. thunbergii
• Hemerocallis ×fallaxlittoralis|Hemerocallis ×fallaxlittoralis Konta & S.Matsumoto = H. littorea × H. thunbergii

A number of hybrid names appear in the horticultural literature but are not recognized as valid by the World Checklist of Selected Plant Families. These include:

• H. ×hybrida
• H. ×ochroleuca
• H. ×stoutiana
• H. ×traubara, H. ×traubiana
• H. ×washingtonia
• H. ×yeldara, H. ×yeldiana

See also

• Arlow Stout - pioneer in the hybridization of daylilies
• Siloam daylilies - over 450 daylily cultivars registered by Pauline Henry.

External links

• The American Hemerocallis Society
• Australian Daylily Society
• Canadian Hemerocallis Society
• Ontario Daylily Society
• Hemerocallis species by the Drs. Lobeck has species, hybrids, and cultivars; links; terms and Latin meanings; images and history of hybrids
• DaylilyDB Daylily Database — Largest online collection of community submitted daylily photos, searchable by cultivar, hybridizer, color, and registration year, providing data and photos.