Daylily

Adaylily,day lilyorditch-lilyis aflowering plantin thegenusHemerocallis/ˌhɛmɪroʊˈkælɪs/,a member of the familyAsphodelaceae,subfamilyHemerocallidoideae,native to Asia. Despite thecommon name,it is not taxonomically classified in thelilygenus. Gardening enthusiasts andhorticulturistshave long bredHemerocallisspecies for their attractiveflowers;a select few species of the genus have edible petals, while some are extremely toxic. Thousands ofcultivarshave been registered by the American Daylily Society, the only internationally recognized registrant according to theInternational Code of Nomenclature for Cultivated Plants.The plants areperennial,bulbousplants, whose common name alludes to its flowers, which typically last about a day.

Daylily
Hemerocallis lilioasphodelus
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Asparagales
Family:	Asphodelaceae
Subfamily:	Hemerocallidoideae
Genus:	Hemerocallis L.
Type species
Hemerocallis lilioasphodelus L.
Synonyms
LilioasphodelusFabr. CamerariaBoehm. in C.G.Ludwig

Description

Daylilies onBlock Island,Rhode Island.

The orange daylily (Hemerocallis fulva) in China

Hemerocallisare herbaceous clump-forming perennials growing from rhizomes,some produce spreadingstolons.They have a fibrous or fibrous-tuberous root system with contractile roots.Thetuberous rootsare used to store nutrients and water. The arching leaves are produced from the base of the plant (basal) and lackpetioles,they are strap-like, long, linearlanceolateleavesand grouped intooppositefans. The crown is the small portion between the leaves and the roots. The large showy flowers are produced onscapes.The slightly irregular shaped flowers are arranged in helicoid cymes, or produced solitarily.The scapes of some species and cultivars produce small leafy proliferations arising from thenodesor inbracts.The proliferations areclonesthat root when planted.

TypicallyHemerocallisflowers have three similarpetalsand threesepals,collectively calledtepals,and each have amidrib.The centermost part of the flower, called the throat, may be a different color than the more distal areas of the tepals. Each flower has sixstamensjoined to theperianthtube, each with a two-lobedanther.The unequal stamen filaments are curved upward with the linear-oblong anthers dorsifixed. The superior ovary is green, with three chambers and the stigma is 3-lobed or capitate. The fruit is acapsule(often erroneously called a pod since botanical pods are found inFabaceae). The fruits may have no seeds (sterile), or many relatively large, shiny, black, roundish seeds.The flowers of most species open in early morning and wither during the following night, possibly replaced by another one on the samescapethe next day. Some species are night-blooming. Thehaploidnumber of chromosomes is eleven.

Taxonomy

Despite their common name, daylilies are not true lilies (plants from the genusLilium,family Liliaceae). Although the flowers ofHemerocallisandLiliumspecies have a similar shape, their growth habits, stems and leaf shapes are distinctive. Before 2009, the scientific classification of daylilies put them into the familyLiliaceae.In 2009, under theAPG III system,daylilies were removed from the family Liliaceae and assigned to the family Xanthorrhoeaceae, subfamily Hemerocallidoideae. Xanthorrhoeaceae was renamed in 2016 to Asphodelaceae in theAPG IV system

Species

Hemerocallis fulva,illustration of 1885

The tawny daylily (Hemerocallis fulva)

Hemerocallis thunbergii

As of January 2020,Plants of the World Onlinerecognized 16 species:

• Hemerocallis citrinaBaroni(syn.H. altissimaStout,H. coreanaNakai) - China, Japan, Korea, Russian Far East
• Hemerocallis coreanaNakai- Japan, Korea, Shandong Province in China
• Hemerocallis darrowianaS.Y.Hu- Sakhalin Island in Russia
• Hemerocallis dumortieriE.Morren- China, Japan, Korea
• Hemerocallis forrestiiDiels- Sichuan + Yunnan Provinces in China
• Hemerocallis fulva(L.) L.(H. sempervirensAraki,H. sendaicaOhwiandH. aurantiacaBakerare now treated as varieties of this species) – orange daylily, tawny daylily, tiger lily, ditch lily - China, Japan, Korea; naturalized in Europe, North America, New Zealand, Indian Subcontinent; considered an invasive weed in some places
• Hemerocallis hakuunensisNakai(syn.H. micranthaNakai) - Korea; includesHemerocallis hongdoensisM.G.Chung & S.S.Kang
• Hemerocallis lilioasphodelusL.(syn.H. flava(L.) L.) – lemon lily, yellow daylily - China, Mongolia, Russian Far East, Siberia, Kazakhstan; naturalized in Europe and North America
• Hemerocallis major(Baker) M.Hotta
• Hemerocallis middendorffiiTrautv. & C.A.Mey.- China, Japan, Korea, Russian Far East

includingH. middendorffiivar.esculenta(Koidz.) Ohwi,syn.H. esculentaKoidz.– Japan;H. middendorffiivar.exaltata,syn.H. exaltataStout

• Hemerocallis minorMill.(syn.H. sulphureaNakai) - China, Mongolia, Korea, Russian Far East, Siberia
• Hemerocallis multifloraStout- Henan Province in China
• Hemerocallis nanaW.W.Sm. & Forrest- Yunnan Province in China
• Hemerocallis plicataStapf- Sichuan + Yunnan Provinces in China
• Hemerocallis thunbergiiBarr(syn.H. serotinaFocke,H. vespertinaHara) - Japan
• Hemerocallis yezoensisH.Hara- Japan, Kuril Islands

Two hybrids are recognized:

• Hemerocallis×exilisSatake=H. fulvavar.angustifolia×H. thunbergii
• Hemerocallis×fallaxlittoralisKonta & 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

Etymology

The nameHemerocalliscomes from theGreekwordsἡμέρα(hēmera) "day" andκαλός(kalos) "beautiful".

Distribution and habitat

Hemerocallisspecies are native toAsia,primarily eastern Asia, includingChina,Korea,Japanand southernSiberia.This genus is popular worldwide because of the showy flowers and hardiness of many kinds. There are over 80,000 registered cultivars. Hundreds of cultivars have fragrant flowers, and more scented cultivars are appearing more frequently in northern hybridization programs. Some earlier blooming cultivars rebloom later in the season, particularly if their capsules, in which seeds are developing, are removed.

Daylilies have been found growing wild for millennia throughout China,Mongolia,northernIndia,Korea, and Japan.There are thousand-year-old Chinese paintings showing orange daylilies that are remarkably similar to the flowers that grace modern gardens.

Daylilies may have been first brought to Europe by traders along the silk routes from Asia.However it was not until 1753 that daylilies were given their botanic name ofHemerocallisby the Swedish naturalistCarl Linnaeus.

Daylilies were first brought to North America by early European immigrants, who packed the roots along with other treasured possessions for the journey to theNew World.By the early 1800s, the plant had become naturalized, and a bright orange clump of flowers was a common sight in many homestead gardens.

The orange or tawny daylily (Hemerocallis fulva), common along roadsides in much of North America, is native to Asia. Along with the lemon lily (Hemerocallis flava), it is the foundational species for most modern cultivars.

Cultivation

As popular as daylilies were for many hundreds of years, it was not until the late 19th century that botanists and gardeners began to experiment with hybridizing the plants. Over the next hundred years, thousands of different hybrids were developed from only a few wild varieties. In fact, most modern hybrids are descended from two types of daylily. One isHemerocallis flava—the yellow lemon lily. The other isHemerocallis fulva,the familiar tawny-orange daylily, also known affectionately as the "ditch lily".

The daylily has been nicknamed "the perfect perennial" by gardeners, due to its brilliant colors, ability to tolerate drought and frost and to thrive in many different climate zones, and for being generally low maintenance. It is a vigorous perennial that lasts for many years in a garden, with very little care and adapts to many different soil and light conditions.Daylilies have a relatively short blooming period, depending on the type. Some will bloom in early spring while others wait until the summer or even autumn. Most daylily plants bloom for 1 through 5 weeks, although some bloom twice in one season ( "rebloomers)".Daylilies are not commonly used as cut flowers for formalflower arranging,yet they make good cut flowers otherwise, as new flowers continue to open on cut stems over several days.

Cultivars

There are more than 100,000 daylilycultivars,the milestone having been achieved in 2024Depending on the species and cultivar, daylilies grow in USDA planthardiness zones1 through 11, making them some of the more adaptablelandscapeplants. Hybridizers have developed the vast majority of cultivars within the last 100 years. The large-flowered, bright yellowHemerocallis'Hyperion', introduced in the 1920s, heralded a return to gardens of the once-dismissed daylily, and is still widely available in the nursery trade. Daylilybreedinghas 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 many sturdy and prolific cultivars sell at reasonable prices of US$20 or less.

Hemerocallisis 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, through 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. Flowers of some cultivars have small areas of bluish shades, particularly in the eyezones.

Other flower traits that hybridizers developed include height, scent, ruffled edges, doubling, contrasting "eyes" in the center of a bloom, fringed edges called ‘teeth’, and an illusion of glitter called "diamond dust". Sought-after improvements include rust resistance, foliage color, variegation, plant disease resistance, and the ability to form large, neat clumps. Hybridizers also seek to make cultivars cold-hardier by crossing evergreen and semi-evergreen plants with dormant varieties.

In recent decades, many hybridizers have focused on breedingtetraploidplants, which tend to have sturdier scapes and tepals than diploids, as well as some flower-color traits that are not found indiploids.Until this trend took root, nearly all daylilies were diploid. Tetraploid cultivars have 44 chromosomes, while triploids have 33 chromosomes and diploids have 22 chromosomes per individual plant. Diploid and tetraploid daylilies cannot be crossed to produce new cultivarsHemerocallis fulva'Europa',H. fulva'Kwanso',H. fulva'Kwanso Variegata',H. fulva'Kwanso Kaempfer',H. fulvavar.maculata,H. fulvavar.angustifolia,andH. fulva'Flore Pleno' are all triploids 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 peoplesynonymize "polymerous" with "double", some polymerous flowers have as many as twice the normal number of sepals and petals.

Formerly daylilies were only available in yellow, pink, fulvous (bronzed), and rosy-fulvous colors, now they come in an assortment of many more color shades and tints thanks to intensive hybridization. They can now be found in nearly every color except pure blue and pure white. Those with yellow, pink, and other pastel flowers may require full sun to bring out all of their colors; darker varieties, including many of those with red and purple flowers are not colorfast in bright sun.

• 
  H.'Ruby Spider'
• 
  H.'Kwanzo' – a triple-floweredtriploidcultivar
• 
  H.'Red Magic'
• 
  H.'Wayside King Royale'
• 
  AHemerocallis lilioasphodeluscultivar growing in Venezuela

Awards

The highest award a cultivar can receive in the United States is the Stout Silver Medal, given in memory of Dr. Arlow Burdette Stout, who is considered to be the father of modern daylily breeding in North America. This annual award—as voted by American Hemerocallis Society (AHS) Garden judges—can be given only to a cultivar that has first received the Award of Merit not less than two years previously. The 2014 winner of the Stout Silver Medal is 'Webster's Pink Wonder', hybridized by Richard Webster and introduced by R. Cobb. A complete list of Stout Silver Medal winners can be seen on the AHS website.

In the UK the following cultivars have gained theRoyal Horticultural Society'sAward of Garden Merit:

• 'All American Chief'
• 'Always Afternoon'
• 'Arctic Snow'
• 'Asterisk'
• 'August Frost'
• 'Beauty to Behold'
• 'Burning Daylight'
• 'Cat Dancer'
• 'Cayenne'
• 'Cherry Eyed Pumpkin'
• H. citrina
• 'Condilla'
• 'Curly Cinnamon Windmill'
• 'Custard Candy'
• 'Eggplant Escapade'
• 'Elegant Candy'
• 'Fooled Me'
• 'Grey Witch'
• 'Holly Dancer'
• 'Jamaican Me Crazy'
• 'Jellyfish Jealousy'
• 'Julie Newmar'
• 'Karen's Curls'
• 'Killer'
• 'Lady Neva'
• 'Lime Frost'
• 'Mahogany Magic'
• 'Mary's Gold'
• 'Moonlit Masquerade'
• 'North Wind Dancer'
• 'Old Tangiers'
• 'Performance Anxiety'
• ‘Pink Damask’
• 'Primal Scream'
• 'Radiant Moonbeam'
• ’Red Precious’
• 'Ruby Spider'
• 'Running Late'
• 'Russian Rhapsody'
• 'Selma Longlegs'
• 'Serena Sunburst'
• 'Sir Modred'
• 'Spider Man'
• 'Stafford'
• 'Strawberry Candy'
• 'Tuxedo Junction'

Pests and diseases

Contarinia quinquenotata,commonly known as the daylily gallmidge,is a small gray insect infesting the flower buds ofHemerocallisspecies causing the flower to remain closed and rot.It is a pest within the horticultural trade in several parts of the world, including Southern and Eastern Europe, the United Kingdom, Canada, and the United States.

Toxicity

Eating too many uncooked flowers of some species can cause diarrhea.Hemerocallisspecies are toxic tocatsand ingestion may be fatal. Treatment is usually successful if started beforekidney failurehas developed.

Uses

Dried golden needles

Daylilies are an economically important group of plants used medicinally, as food, and as horticultural plants. They have been cultivated in East Asia starting in China for thousands of years.Hemerocallin, a rootneurotoxin,has been used as poison and therapeutically as part of traditional orientalmedicine.Some flowers of certain species such asHemerocallis citrinaare used inChinese cuisine.They are sold fresh or dried inAsian marketsasgum jum(Kim châminChinese;pinyin: jīn zhēn) oryellow flower vegetables(Rau kim châminChinese;pinyin: huáng huā cài). These are used inhot and sour soup,daylily soup ( kim châm hoa canh ),Buddha's delight,andmoo shu pork.The tubers and young leaves ofH. fulvacan be eaten raw or cooked. The flowers are more palatable upon cooking.

Moreover, Daylilies are among the most popular North American garden plants. Registered cultivars ofHemerocallisnow exceed 38,000, including more than 13,000 named clones ofH. fulva.

See also

• Arlow Stout– pioneer in the hybridization of daylilies
• Contarinia quinquenotata– daylily gall midge
• Hemerocallis'Duke of Durham'
• Siloam daylilies– over 450 daylily cultivars registered by Pauline Henry.
• List of plants known as lily

External links

• "Hemerocallis".The Plant List.Royal Botanic Gardens, Kew.Note that this website has been superseded byWorld Flora Online
• "Hemerocallis".Tropicos.Missouri Botanical Garden.
• Hemerocallis speciesby the Drs. Plodeck has species, hybrids, and cultivars; links; terms and Latin meanings; images and history of hybrids
• Charlotte's Daylily DiaryCharlotte Chamitoff's Daylily Diary is a wealth of information on growing daylilies and daylily hybridizing. The website is full of daylily images and information about individual hybridizers.
• Charlotte's International Garden of the WeekFor more than a decade, Charlotte Chamitoff has delighted daylily lovers with her Garden of the Week. See daylily gardens from all over the world.

Daylily societies

• The American Hemerocallis Society
• Australian Daylily Society
• Canadian Hemerocallis SocietyArchived2012-01-26 at theWayback Machine
• National Capital Daylily ClubArchived2016-11-13 at theWayback Machine
• Northern Virginia Daylily Society
• Ontario Daylily SocietyArchived2019-03-21 at theWayback Machine
• Region 4 of the American Hemerocallis Society
• The British Hosta and Hemerocallis Society
• The Metropolitan Columbus Daylily Society