Forsythia

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Lamiids
Ordo: Lamiales

Familia: Oleaceae
Tribus: Forsythieae
Genus: Forsythia
Sectiones: F. sect. Forsythia – F. sect. Giralidianae

Intersectional nothospecies: F. × intermedia – F. × kobendzae – F. × variabilis
Name

Forsythia Vahl (1804)

Type species: F. suspensa (Thunb.) Vahl

Synonyms

Homotypic
Rangium Juss. in F.Cuvier, Dict. Sci. Nat. 24: 200 (1822).

Species overview

F. europaea – F. giraldiana – F. japonica – F. koreana – F. likiangensis – F. mandschurica – F. mira – F. ovata – F. saxatilis – F. suspensa – F. togashii – F. velutina – F. viridissima
References

Vahl, M. 1804: Enum. Pl. 1: 39.

Vernacular names
беларуская: Фарзіцыя
català: Forsítia
kaszëbsczi: Fòrsëcjô
čeština: zlatice
Deutsch: Forsythie
Esperanto: Forsitio
فارسی: یاس زرد
suomi: Onnenpensaat
Gaeilge: Foirsítia
hrvatski: Forzicija
magyar: Aranyfa
հայերեն: Ոսկեզանգ
日本語: レンギョウ
қазақша: Форсайтия
한국어: 개나리속
lietuvių: Forsitija
Nederlands: Forsythia
norsk: Gullbuskslekta
polski: Forsycja
română: Forsiția
русский: Форсайтия, Форзиция
srpskohrvatski / српскохрватски: Forzicija
slovenčina: zlatovka
српски / srpski: Форситија
svenska: Forsythiasläktet
Türkçe: Altınçanağı, Altınçanak
українська: Форзиція
粵語: 連翹屬
中文: 连翘属

Forsythia /fɔːrˈsɪθiə/, /fɔːrˈsaɪθiə/[2] is a genus of flowering plants in the olive family Oleaceae. There are about 11 species, mostly native to eastern Asia, but one native to southeastern Europe.[1] Forsythia – also one of the plant's common names – is named after William Forsyth.[3][4][5]

Description

Forsythia are deciduous shrubs typically growing to a height of 1–3 m (3 ft 3 in–9 ft 10 in) and, rarely, up to 6 m (20 ft) with rough grey-brown bark. The leaves are borne oppositely and are usually simple, though sometimes trifoliate with a basal pair of small leaflets; they range between 2 and 10 cm (0.79 and 3.94 in) in length and, rarely, up to 15 cm (5.9 in), with a margin that is serrated or entire (smooth). Twigs may be hollow or chambered, depending on the species.[6]

The flowers are produced in the early spring before the leaves, bright yellow with a deeply four-lobed flower, the petals joined only at the base. These become pendent in rainy weather thus shielding the reproductive parts. The fruit is a dry capsule, containing several winged seeds.[3][7]

It is widely stated that forsythia flowers are able to produce lactose. Lactose is very rarely established in other natural sources except milk. However, the presence of lactose could not be confirmed.[8]

The genus is named after William Forsyth (1737–1804), a Scottish botanist who was royal head gardener and a founding member of the Royal Horticultural Society.[9]
Species
An adaptation of the warming stripes that shows how the flowering time of Forsythia suspensa in Bavaria has changed between 1951 and 2020

The following species of Forsythia have been documented:[3][4][5][7][10][11][12]

Forsythia europaea Degen & Bald. – Balkans in Albania and Serbia
Forsythia giraldiana Lingelsh. – northwest China
Forsythia × intermedia Zabel – an artificial garden hybrid between F. suspensa and F. viridissima[13]
Forsythia japonica Makino – Japan
Forsythia koreana (Rehder) Nakai – Korea
Forsythia likiangensis Ching & K.M.Feng – southwest China
Forsythia × mandschurica Uyeki – northeast China
Forsythia mira M.C.Chang – north central China
Forsythia ovata Nakai – Korea
Forsythia saxatilis (Nakai) Nakai – Korea
Forsythia suspensa (Thunb.) Vahl – eastern and central China
Forsythia togashii H.Hara – Japan (Shōdoshima)
Forsythia velutina Nakai – Korea
Forsythia viridissima Lindl. – eastern China

A genetic study[14] does not fully match the traditionally accepted species listed above, and groups the species in four clades: (1) F. suspensa; (2) F. europaea—F. giraldiana; (3) F. ovata—F. japonica—F. viridissima; and (4) F. koreana—F. mandschurica—F. saxatilis. Of the additional species, F. koreana is usually cited as a variety of F. viridissima, and F. saxatilis as a variety of F. japonica;[15] the genetic evidence suggests they may be better treated as distinct species.

Forsythias are used as food plants by the larvae of some Lepidoptera species including the brown-tail and Gothic moth.
Garden history
Forsythia in full bloom

Two species of forsythia are at the heart of the selected forms and garden hybrids: Forsythia suspensa and F. viridissima. "These two species are, as it were, the founder-members of the forsythia family" writes Alice Coats; they were the earliest species brought into Western gardens from the Far East and they have each played a role in the modern garden shrubs.[16]

Forsythia suspensa, the first to be noticed by a Westerner, was seen in a Japanese garden by the botanist-surgeon Carl Peter Thunberg, who included it (as a lilac) in his Flora Japonica 1784. Thunberg's professional connections lay with the Dutch East India Company, and F. suspensa reached Holland first, by 1833. In England, when it was being offered by Veitch Nurseries in Exeter at mid-century, it was still considered a rarity. Not all the varieties of suspensa are splaying and drooping, best seen hanging over a retaining wall; an erect form found by Fortune near Peking in 1861 was for a time classed as a species—F. fortunei.[16]

Forsythia viridissma, meanwhile, had overtaken it in European gardens. The Scottish plant-hunter Robert Fortune "discovered" it—in a mandarin garden of the coastal city of Chusan (Zhoushan)—before he ever saw it growing wild in the mountains in Zhejiang province.[16]
Forsythia × intermedia in Heidelberg, Germany

Forsythia × intermedia, as its name suggests, is a hybrid of F. suspensa and F. viridissima, introduced in continental Europe about 1880. Repeated crosses of the same two parents have made reiterations of F. × intermedia quite variable. A bud sport of a particularly showy (spectabilis) form is widely marketed as F. × intermedia 'Lynwood Variety'.[16] This cultivar has gained the Royal Horticultural Society's Award of Garden Merit,[17] as have F. × intermedia Week End 'Courtalyn'[18] and F. Marée d'Or 'Courtasol'.[19]

About the time of the First World War further species were discovered by plant hunters in China: F. giraldian (found in Gansu, 1910) and F. ovata (collected from seed in Korea by E.H. "Chinese" Wilson) have been particularly useful as seed parents in 20th-century American crosses.[16]
Cultivation and uses

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Autumn leaf color

Forsythias are popular early spring flowering shrubs in gardens and parks, especially during Eastertide; Forsythias are nicknamed the Easter Tree, the symbol of the coming spring.[20] Two are commonly cultivated for ornament, Forsythia × intermedia and Forsythia suspensa. They are both spring flowering shrubs, with yellow flowers. They are grown and prized for being tough, reliable garden plants. Forsythia × intermedia is the more commonly grown, is smaller, has an upright habit, and produces strongly coloured flowers. Forsythia suspensa is a large to very large shrub, can be grown as a weeping shrub on banks, and has paler flowers. Many named garden cultivars can also be found. Forsythia is frequently kept indoors in the early spring.[7]

Commercial propagation is usually by cuttings, taken from green wood after flowering in late spring to early summer; alternatively, cuttings may be taken between November and February.[7] Low hanging boughs often take root, and can be removed for transplanting. A common practice (known as layering) is to place a weight over a branch to keep it on the ground and, after it has rooted, to dig up the roots and cut the rooted part from the main branch; this can then be planted.

Forsythia suspensa is considered one of the 50 fundamental herbs in Chinese herbology.[21] Forsythia sticks are used to bow a Korean string instrument called ajaeng.[22]
In popular culture

In the 2011 film Contagion, Forsythia is used as a conspiracy theorist's supposed "cure", causing pharmacies to be over-run.[23][24]
Common names

In some regions, the plant may be known as Easter tree and the flowers as yellow bells.

References

Kew World Checklist of Selected Plant Families
Sunset Western Garden Book, 1995:606–607
Flora of China: Forsythia
Flora Europaea: Forsythia
St Andrews Botanic Garden: Plant of the Month: Forsythia Archived 2007-06-25 at the Wayback Machine
http://arnoldia.arboretum.harvard.edu/pdf/articles/1950-10--the-forsythias.pdf
Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan ISBN 0-333-47494-5.
Toba, T., Nagashima, S. and Adachi, S. (1991), Is lactose really present in plants?. Journal of the Science of Food and Agriculture, 54: 305–308. doi:10.1002/jsfa.2740540217
Forsythia by Green Deane at Eat the Weeds. Accessed April 2013
University of Oxford, Oleaceae information site: Forsythia
"Government of Alberta, Agriculture and Rural Development". Archived from the original on 2015-03-27. Retrieved 2008-06-17.
"Forsythia Vahl". www.worldfloraonline.org. Retrieved 2021-04-04.
"Forsythia × intermedia Zabel". Plants of the World Online. Kew Science. Retrieved 2021-04-04.
Kim, K.-J. (1999). Molecular phylogeny of Forsythia (Oleaceae) based on chloroplast DNA variation. P. Syst. Evol. 218: 113-123. Abstract.
Germplasm Resources Information Network: Forsythia Archived 2000-06-05 at the Wayback Machine
Coats, Alice M. (1965). Garden shrubs and their histories. Dutton.
"RHS Plant Selector – Forsythia × intermedia 'Lynwood Variety'". Retrieved 7 June 2020.
"RHS Plant Selector – Forsythia × intermedia Week End 'Courtalyn'". Retrieved 7 June 2020.
"RHS Plant Selector – Forsythia Marée d'Or 'Courtasol'". Retrieved 7 June 2020.
"Forsythia viridissima". NCSU. Retrieved 2020-03-20.
Vahl, Thunb (2019-05-02). "Forsythia Lian Qiao Weeping PFAF Plant Database". Plants for a Future.
"Ajaeng" (in Korean). Culture Content. Archived from the original on 2018-04-14. Retrieved 2020-03-20.
Sperling, Nicole (2020-03-04). "'Contagion,' Steven Soderbergh's 2011 Thriller, Is Climbing Up the Charts". New York Times. Retrieved 2020-03-20.
Hou, Chia-Yi (2020-02-05). "The movie 'Contagion' is trending again". The Hill. Retrieved 2020-03-05.