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Hemerocallis lilioasphodelus.jpg
Hemerocallis lilioasphodelus
Scientific classification e
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Asphodelaceae
Subfamily: Hemerocallidoideae
Genus: Hemerocallis
Type species
Hemerocallis lilioasphodelus
  • Lilioasphodelus Fabr.
  • Cameraria Boehm. in C.G.Ludwig

A daylily or day lily is a flowering plant in the genus Hemerocallis /ˌhɛmɪrˈkælɪs/,[2] a member of the family Asphodelaceae, subfamily Hemerocallidoideae. Despite the common name, it is not in fact a lily. Gardening enthusiasts and horticulturists have long bred daylily species for their attractive flowers. Thousands of cultivars have been registered by local and international Hemerocallis societies.[3]

The name Hemerocallis comes from the Greek words ἡμέρα (hēmera) "day" and καλός (kalos) "beautiful".


Daylilies on Block Island, Rhode Island.
The orange daylily (Hemerocallis fulva) in China

Daylilies are perennial plants, whose name alludes to its flowers, which typically last about a day. The flowers of most species open in early morning and wither during the following night, possibly replaced by another one on the same scape the next day. Some species are night-blooming. Daylilies are not commonly used as cut flowers for formal flower arranging, yet they make good cut flowers otherwise, as new flowers continue to open on cut stems over several days.[citation needed]

Hemerocallis is native to Asia, primarily eastern Asia, including China, Korea, and Japan. 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.[citation needed]

Despite the name, daylilies are not true lilies, although the flower has a similar shape. Before 2009, the scientific classification of daylilies put them into the family Liliaceae. Unlike daylilies, which have a fibrous root system, Liliaceae species grow from bulbs and, if ingested, are harmful to humans and animals. It is a common misconception that daylilies share the toxic properties of true lilies.

In 2009, under the APG 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 the APG IV system.

Most kinds of daylilies occur as clumps, each of which has leaves, a crown, scapes, flowers, and roots. The long, linear lanceolate leaves are grouped into opposite fans with arching leaves. The crown is the small white portion between the leaves and the roots. Along the scape of some kinds of daylilies, small leafy proliferations form at nodes or in bracts. A proliferation forms roots when planted and is an exact clone of its parent plant. Many kinds of daylilies have thickened roots in which they store food and water.

A normal, single daylily flower has three petals and three sepals, collectively called tepals, each with a midrib in either the same basic color or a different color. The centermost part of the flower, called the throat, may be a different color than the more distal areas of the tepals. Each flower usually has six stamens, each with a two-lobed anther. After successful pollination, a flower forms a botanical capsule (often erroneously called a pod since botanical pods are found in Fabaceae, not Hemerocallis).

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.

Although the buds and flowers are often used by humans in gourmet dishes, Hemerocallis species are toxic to cats and ingestion may be fatal. Treatment is usually successful if started before kidney failure has developed.[4]



Hemerocallis fulva, illustration of 1885
The tawny daylily (Hemerocallis fulva)
Hemerocallis thunbergii

As of January 2020, Plants of the World Online recognized 16 species:[5]

including H. middendorffii var. esculenta (Koidz.) Ohwi, syn. H. esculenta Koidz. – Japan; H. middendorffii var. exaltata, syn. H. exaltata Stout

Two hybrids are recognized:[6]

  • Hemerocallis × exilis Satake = H. fulva var. angustifolia × H. thunbergii
  • 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:[6]

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


Daylilies have been found growing wild for millennia throughout China, Mongolia, northern India, Korea, and Japan.[7] 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.[8] However it was not until 1753 that daylilies were given their botanic name of Hemerocallis by the Swedish naturalist Carl 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 the New 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.

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 is Hemerocallis flava—the yellow lemon lily. The other is Hemerocallis fulva, the familiar tawny-orange daylily, also known affectionately as the "ditch lily."[9]


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.[10] 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)".[11]


There are more than 35,000 daylily cultivars.[10] Depending on the species and cultivar, daylilies grow in USDA plant hardiness zones 1 through 11, making them 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,[citation needed] but many sturdy and prolific cultivars sell at reasonable prices of US$20 or less.

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, 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 cobalt blue.

Other flower traits that hybridizers developed include height, scent, ruffled edges, contrasting "eyes" in the center of a bloom, and an illusion of glitter called "diamond dust." Sought-after improvements include 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 breeding tetraploid plants, which tend to have sturdier scapes and tepals than diploids, as well as 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. Diploid and tetraploid daylilies cannot be crossed to produce new cultivars[12] 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 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 people[who?] synonymize "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.


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 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.[13]

In the UK the following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-[14]

  • 'All American Chief'
  • 'Always Afternoon'
  • 'Arctic Snow'
  • 'Asterisk'
  • 'August Frost'
  • 'Beauty to Behold'
  • 'Burning Daylight'[15]
  • '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’[16]
  • 'Primal Scream'
  • 'Radiant Moonbeam'
  • ’Red Precious’[17]
  • 'Ruby Spider'[18]
  • 'Running Late'
  • 'Russian Rhapsody'
  • 'Selma Longlegs'
  • 'Serena Sunburst'[19]
  • 'Sir Modred'[20]
  • 'Spider Man'
  • 'Stafford'[21]
  • 'Strawberry Candy'
  • 'Tuxedo Junction'[22]


Contarinia quinquenotata, commonly known as the daylily gall midge, is a small gray insect infesting the flower buds of Hemerocallis species causing the flower to remain closed and rot.[23] 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.[24]


Dried golden needles

The flowers of Hemerocallis citrina are edible and are used in Chinese cuisine.[25] They are sold (fresh or dried) in Asian markets as gum jum (金针 in Chinese; pinyin: jīn zhēn) or yellow flower vegetables (黃花菜 in Chinese; pinyin: huáng huā cài). They are used in hot and sour soup, daylily soup (金針花湯), Buddha's delight, and moo shu pork.

See also[edit]


  1. ^ "Hemerocallis". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. ^ Sunset Western Garden Book, 1995:606–607
  3. ^ "International Daylily Groups". American Hemerocallis Society.
  4. ^ Fitzgerald, K.T. (2010). "Lily toxicity in the cat". Topics in Companion Animal Medicine. 25 (4): 213–217. doi:10.1053/j.tcam.2010.09.006. PMID 21147474.
  5. ^ "Hemerocallis L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2020-01-16.
  6. ^ a b World Checklist of Selected Plant Families, The Board of Trustees of the Royal Botanic Gardens, Kew, retrieved July 19, 2014
  7. ^ Leatherbarrow, Liesbeth (1999). 101 Best Plants for the Prairies. Madison, Wisconsin: Fifth House Publishers. ISBN 978-1894004305.
  8. ^ Halpin, Anne Moyer (1992). The Naming of Flowers. Stamford, Connecticut: Longmeadow Press. ISBN 978-0681416543.
  9. ^ Cassidy, Frederic Gomes (2002). Dictionary of American Regional English. Cambridge, Massachusetts: Harvard University Press. ISBN 978-0681416543.
  10. ^ a b "Growing daylilies".
  11. ^ "Dayliles Frequently Asked Questions". American Hemerocallis Society. American Hemerocallis Society, Inc. Retrieved 12 June 2012.
  12. ^ Daylilies Archived 2007-11-06 at the Wayback Machine undated info page at University of Nebraska. Accessed August 1, 2007.
  13. ^ "AHS Awards and Honors: Stout Medal Winners".
  14. ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 47. Retrieved 3 March 2018.
  15. ^ "RHS Plantfinder - Hemerocallis 'Burning Daylight'". Retrieved 2 March 2018.
  16. ^ "RHS Plantfinder - Hemerocallis 'Pink Damask'". Retrieved 2 March 2018.
  17. ^ "RHS Plantfinder - Hemerocallis 'Red Precious'". Retrieved 2 March 2018.
  18. ^ "RHS Plantfinder - Hemerocallis 'Ruby Spider'". Retrieved 2 March 2018.
  19. ^ "RHS Plantfinder - Hemerocallis 'Serena Sunburst'". Retrieved 2 March 2018.
  20. ^ "RHS Plantfinder - Hemerocallis 'Sir Modred'". Retrieved 2 March 2018.
  21. ^ "RHS Plantfinder - Hemerocallis 'Stafford'". Retrieved 2 March 2018.
  22. ^ "Hemerocallis 'Tuxedo Junction'". RHS. Retrieved 16 January 2020.
  23. ^ "Hemerocallis Gall Midge". American Hemerocallis Society. Retrieved 5 May 2019.
  24. ^ "Continaria quinquenotata". Phytosanitary Alert System. North American Plant Protection Organization. 2014. Retrieved 5 May 2019.
  25. ^ Hemerocallis citrina

External links[edit]

Daylily societies[edit]