Akebia quinata
(five-leaf akebia)

Pictures

Picture	Title	Caption	Copyright
Title Flower Caption Five-leafed akebia (Akebia quinata); female, male, April, 2009 Copyright ©Ashley Basil - 2009 - CC BY 2.0	Flower	Five-leafed akebia (Akebia quinata); female, male, April, 2009	©Ashley Basil - 2009 - CC BY 2.0
Title Seed pod Caption Five-leafed akebia (Akebia quinata); Akebia pod, September, 2006 Copyright ©Hunda - 2006 - CC BY-SA 2.0	Seed pod	Five-leafed akebia (Akebia quinata); Akebia pod, September, 2006	©Hunda - 2006 - CC BY-SA 2.0

Identity

Preferred Scientific Name

• Akebia quinata (Houtt.) Decne.

Preferred Common Name

• five-leaf akebia

Other Scientific Names

• Akebia micrantha Nakai
• Akebia quinata f. albiflora Y.N.Lee
• Akebia quinata f. diplochlamys (Makino) T. Shimizu
• Akebia quinata f. polyphylla (Nakai) Hiyama
• Akebia quinata f. viridiflora Makino
• Akebia quinata var. diplochlamys Makino
• Akebia quinata var. longeracemosa (Matsum.) Rehder & E.H.Wilson
• Akebia quinata var. polyphylla Nakai
• Akebia quinata var. yechi W.C.Cheng
• Rajania quinata Thunb. ex Houtt

International Common Names

• English: akebia; chocolate-vine; fiveleaf; raisin vine
• French: akébia à cinq folioles or feuilles
• Russian: akebia pyaternoye
• Chinese: bai mu tong; mu tong; son ye mu tong

Local Common Names

• Germany: fingerblättrige akebie; fuenfblaettrige akebie
• Netherlands: klimbes; schijnaugurk

EPPO code

• AKEQI (Akebia quinata)

Summary of Invasiveness

A. quinata is a highly invasive, aggressive vine native to eastern Asia, eastern central China, Japan and Korea. It has been introduced into Canada, Europe, Oceania and the USA. Here it poses a dangerous risk to ecosystems by readily naturalizing in suitable climates. A. quinata grows quickly by vegetative means where it can outcompete and replace existing flora including understory shrubs and young trees. Its dense growth shades out sunlight preventing seed germination and establishment of seedlings of native plants. The dense shade created by A. quinata can kill existing species.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Ranunculales
•                         Family: Lardizabalaceae
•                             Genus: Akebia
•                                 Species: Akebia quinata

Notes on Taxonomy and Nomenclature

A. quinata is one of approximately 30–50 species in the family Lardizabalaceae (Watson and Dallwitz, 1992; Kofuji et al., 1994; Li et al., 2010; Schweingruber et al., 2011). The family Lardizabalaceae consists of approximately 40 species in seven genera. The genus Akebia is one of these and contains a total of six species (Christenhusz, 2012).

A. quinata was first circumscribed in 1779 as Rajania quinata by Maarten Houttuyn based on a specimen collected by Carl Peter Thunberg in Japan, most likely near Nagasaki (Christenhusz, 2012; Missouri Botanical Garden, 2012).

The name A. quinata var. longiracemosa is not a variety or synonym of A. quinata, but rather a synonym of A. longiracemose.

Description

A. quinata is a liana, a vigorous, woody, deciduous, climbing vine. The stems are greyish brown, slender and cylindrical with small, prominent lenticels that have the shape of a flat ring or disk. Its pale red-brown winter buds' outer scales overlap like roof tiles. The petiole is slender (4.5–10 cm); its petiolules are slender (0.8–1.5(–2.5) cm). The leaves have several leaflets (typically 5–7) whose midribs all radiate from one point. The leaves alternate along the stems or cluster on the branchlets and are divided into five, or sometimes three to four or up to seven leaflets. The papery leaflets are obovate to obovate-elliptic. The leaflets are abaxially glaucous (whitish underneath), adaxially dark green (dark green above) with bases which are rounded to broadly cuneate. The apex, that is the point furthest from the point of attachment, is rounded and usually emarginated (notched) or cuspidate (with a point). The lateral leaflets measure 2–5 x 1.5–2.5 cm, while the terminal leaflets are 2.5–5(–7) cm. The racemes are clustered or bundled together measuring 6–12 cm. The scaly bracts are arranged like roof tiles. The stem that attaches or supports single flowers to the main stem of the inflorescence is approximately 2.5 cm and is located on short branches. The small, purple-brown, hanging flowers are held in groups of two to five and have somewhat fragrant chocolate or, in some sources, vanilla scent.

Flowers are monoecious, apetalous, with both staminate (male) and pistillate (female) flowers appearing in the same raceme. A. quinata produces staminate and pistillate flowers that are found in pendulous, racemose clusters (Payne and Seago, 1968). Male flowers are 4–8(–11) mm. The stem that attaches single flowers to the main stem slender is 7-10 mm with three sepals 3(-5), pale purple, occasionally pale green or white, broadly cucullate-ovate, 6–8 x 4–6 mm, apex rounded. Stamens 6 (or 7), straight at first, incurved at length; filaments very short; anthers oblong. Pistillodes 3–6, small. Female flowers, pedicel slender, 2–4(–5) cm. Sepals dark purple, occasionally green or white, broadly elliptic to suborbicular, 1–2 x 0.8–1.5 cm. Staminode 6–9. Carpels 3–6(–9). The sausage-shaped, purplish pods of the mature fruit are straight or slightly incurved, oblong to ellipsoid, 5–8 x 3–4 cm. Seeds ovoid-oblong, compressed, pulp white; seed coat brown to black, shiny (Brand, 2001; Flora of North America Editorial Committee, 2013; Missouri Botanical Gardens, 2013)

Distribution

A. quinata is a well-documented, adventive vine native to eastern Asia, eastern central China, Japan and Korea. It has been introduced into parts of North America, Europe and Australia.

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

A. quinata is reported to have been introduced into cultivation in the USA 1845 by Robert Fortune during his first visit to China, from the island of Chusan, southeast of Shanghai (Christenhusz and Rix, 2012).

By the mid nineteenth century A. quinata was widely known to ornamental horticulturists in both Europe and the USA. Its ability to rapidly provide cover in either sun or shade for trellises, fences and walls meant that it was sought after as a landscape ornamental (Missouri Botanical Gardens, 2013). A Chicago, Illinois (USA) newspaper extolled the virtues and hardiness of Akebia, along with Clematis and Wisteria (Pomeroy, 1873).

Introductions

Risk of Introduction

A. quinata is a well-known and easily found ornamental landscape plant. The primary pathway for introduction is the ornamental landscape, horticulture and nursery trade in Europe, Australia and North America and this species is still sold as such. A. quinata is listed as a species to be observed in the Mediterranean Basin (Brunel et al., 2010).

Habitat

A. quinata is both shade and drought tolerant. It can invade many types of ecosystems. In China it was reported by Robert Fortune as growing on the lower side of hills, in hedges and climbing on trees (Lindley, 1847). A. quinata can be found along forest margins and streams, as well as scrub growth on mountain slopes at 300-1500 m in China (Flora of China Editorial Committee, 2013).

Habitat List

Biology and Ecology

Genetics

A diploid number of 2n = 32 has been reported for A. quinata (Angelo, 2011). A. quinata can cross with A. trifoliata to create the hybrid Akebia x pentaphylla.

Reproductive Biology

A. quinata reproduces vegetatively (clonally). Flowers of A. quinata are "strongly" protogynous, self-incompatible and require cross pollination. The main pollinators observed are hoverfies (Syrphidae family), honey bees (Apis species) and small solitary bees, although wind pollination is also suspected due to specific inflorescence structures and shapes (Payne and Seago, 1968; Kawagoe and Suzuki, 2002; Li et al., 2010). 

Physiology and Phenology

A. quinata is an apical vine twining from right to left (dextrally in relation to its main stem) as it moves upwards (Payne and Seago, 1968). A. quinata flowers in spring (March–May) and fruits in autumn (September–October); the female flowers open a few days before the male inflorescence (Flora of China Editorial Committee, 2013; Sonday and Burnham, 2014). The flowering period typically lasts between 30 and 60 days (Li et al., 2010).

Fruit set in the wild is usually low according to Li et al. (2010); however the authors report observance of heavy fruit loads under orchard cultivation where there is a short, two year juvenile period prior to fruiting.

Population Size and Structure

Heavy harvest of Akebia species fruit for medicinal purposes in the wild has resulted in a population decline in China (Li et al., 2010).

Environmental Requirements

A. quinata is both shade and drought tolerant. It can invade many types of ecosystems preferring light (sandy), medium (loamy) and heavy (clay) soils and soils rich in iron and aluminium (Li et al., 2010). A. quinata requires a well-drained yet moist soil for optimal growth and reproduction. This species will grow on a north facing slope, as well as thriving in full sun. It is hardy to about –20°C. Its early spring growth on both young and mature plants is frost-tender. In mild, temperate climates A. quinata may be semi-evergreen (Swearingen et al., 2009; ISSG, 2012).

Climate

Air Temperature

Rainfall

Natural enemies

Notes on Natural Enemies

No serious pests or diseases have been reported for A. quinata (Missouri Botanical Gardens, 2013). However, in Italy, powdery mildew (order Erysiphales) has been reported on this species (Garibaldi et al., 2004).

Four species of fungi have been found in association with members of the genus Akebia. These include Microsphaera akebiae [Erysiphe akebiae], Microsphaera penicillata [Erysiphe penicillata], Muyocopron smilacis and Aecidium akebiae (Zheng et al., 2006). In addition to this three arthropod species have been found associated with Akebia species: Evecliptopera decurrens, Ophideres fullonica [Eudocima fullonia] and Archips asiaticus (Zheng et al., 2006).

Means of Movement and Dispersal

Natural Dispersal

A. quinata primarily spreads over short distances by vegetative means.

Vector Transmission

Birds, animals and human are all involved in seed dispersal (Li et al., 2010).

Intentional Introduction

A. quinata is readily available in the garden and landscape trade and horticultural industry in North America and Europe and as a result is intentionally introduced into new areas (BALKEP, 2014; Dave’s Garden, 2014; Royal Horticultural Society, 2014).

Impact Summary

Environmental Impact

Impact on Habitats

A. quinata outcompetes indigenous species through its suppression of light, its consumption of water, nutrients and space (ISSG, 2012).

Impact on Biodiversity

A. quinata is reported to outcompete and displace native plant species thereby decreasing biodiversity (ISSG, 2012).

Risk and Impact Factors

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Pioneering in disturbed areas
• Tolerant of shade
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Reproduces asexually
• Has high genetic variability

• Altered trophic level
• Damaged ecosystem services
• Ecosystem change/ habitat alteration
• Modification of hydrology
• Modification of nutrient regime
• Modification of successional patterns
• Negatively impacts forestry
• Reduced native biodiversity
• Threat to/ loss of endangered species
• Threat to/ loss of native species

• Competition - monopolizing resources
• Competition - shading
• Competition - smothering
• Competition - strangling
• Rapid growth

• Highly likely to be transported internationally deliberately

Uses

Economic Value

A. quinata is a specimen plant used in ornamental gardens and managed landscapes (Brand, 2001; Missouri Botanical Gardens, 2013; Dave’s Garden, 2014; Royal Horticultural Society, 2014). A. quinata is used as a ground cover and climbing ornamental specimen. The use of Akebia as an ornamental has a long history in the USA. The leaves of A. quinata may be mixed in salads or used fresh and dry for tea and in herb vinegar mixtures. The bitter skin of the fruit reportedly can be fried and eaten. The peeled stems are very pliable and can be used in basket making (BALKEP, 2014).

Social Benefit

In China, the fruits of Akebia species including A. quinata have a use in traditional medicines in which urinary tract infections, scanty lactation and rheumatoid arthritis are treated. In addition, the fruits have been shown to have stimulatory effects on blood circulation and to have anticancer properties (Li et al., 2010). A. quinata seeds produce an oil used in traditional soap making in China (Zheng et al., 2006).

Similarities to Other Species/Conditions

Species of Aristolochia resemble A. quinata (ISSG, 2012). Aristolochia species have purple flowers but have spade-shaped simple leaves. At first sight A. quinata may be confused with Virginia creeper, Parthenocissus quinquefolia, an indigenous North American species (Gray et al., 2009). However the leaflets of P. quinquefolia have toothed edges compared to the smooth edges of A. quinata. A. quinata may also be confused with Wisteria frutescens and W. sinensis (Sonday and Burnham, 2014), however the leaflets of Wisteria species are not arranged palmately.

Prevention and Control

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Control

Physical/Mechanical Control

Vines of A. quinata which are growing on the ground can be pulled by hand. For climbing vines, first cut the stems near the ground to kill the upper portions in the tree canopies. The plant below the cut will remain alive and must be pulled repeatedly over many growing seasons. Young vines that regrow can be cut any time of year using a weed whip or mower. Vines must be cut down repeatedly over several years until no regrowth occurs. Thorough mulching may be an additional tool to suppress regrowth after an initial pulling and cutting (Swearingen et al., 2009). 

Chemical Control

Treatment with 2-4% triclopyr in water can be applied to control A. quinata. Best results occur when treated during spring/early summer many desirable plants are present during this time. Therefore a fall/dormant treatment followed by spot treatments during the growing season is often advisable (Zedaker and Burch, 2001). To control climbing vines in trees, cut large stems and immediately treat the stumps with a herbicide, triclopyr or a glyphosate. A subsequent foliar application of may be required to control new seedlings and any resprouts (Bargeron et al., 2008). 

Gaps in Knowledge/Research Needs

More research is needed on the possible control of A. quinata by biological means and its impact on rare/endangered species.

References

Angelo R, 2011. Atlas of the flora of New England: dicots - magnoliidae & hamamelidae: families F-M. ttp://neatlas.org/Neatlas4/Neatlas4Fam-F-M

Atlas of Living Australia, 2012. Atlas of Living Australia. Canberra ACT, Australia: GBIF. www.ala.org.au

BALKEP, 2014. Balken ecology project. http://www.balkep.org/

Bargeron CT, Minteer CR, Evans CW, Moorhead DJ, Douce GK, Reardon RC, 2008. Chocolate vine. Invasive plants of the US. http://www.invasive.org/weedcd/species/10090.htm

Baus E, Branquart E, Vanderhoeven S, Landuyt WVan, Rossum FVan, Verloove F, 2009. Invasive species in Belgium. The Belgian Biodiversity Platform. http://ias.biodiversity.be/

Brand M, 2001. UConn plant database., USA: University of Connecticut. http://hort.uconn.edu/

Brunel S, Schrader G, Brundu G, Fried G, 2010. Emerging invasive alien plants for the Mediterranean Basin. Bulletin OEPP/EPPO Bulletin, 40(2):219-238. http://www.blackwell-synergy.com/loi/epp

Christenhusz MJM, 2012. An overview of lardizabalaceae. Curtis's Botanical Magazine, 29(3):235-276. http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1467-8748

Christenhusz MJM, Rix M, 2012. Akenia quinata. Curtis's Botanical Magazine, 29(3):284-289

Dave's Garden, 2014. Chocolate vine, five-leaf akebia, raisin vine, Akebia quinata. Dave's Garden (online). http://davesgarden.com/guides/pf/go/369/#b

EPPO, 2012. Akebia quinata (Lardizabalaceae): chocolate vine or fiveleaf., France: EPPO. http://www.eppo.int/INVASIVE_PLANTS/observation_list/Akebia_quinata.htm

EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm

Flora of China Editorial Committee, 2013. Flora of China web. Cambridge, USA: Harvard University Herbaria. http://flora.huh.harvard.edu/china/

Flora of North America Editorial Committee, 2013. Flora of North America North of Mexico. Flora of North America. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=1

Garibaldi A, Bertetti D, Gullino ML, 2004. First report of powdery mildew (Oidium sp.) on Akebia quinata in Italy. Plant Disease, 88(6):682

GBIF, 2012. Global Biodiversity Information Facility. Global Biodiversity Information Facility (GBIF). http://data.gbif.org

Glasnovik and Pecnikar PVF, 2010. Akebia quinata (Houtt.) Dcne., new species for Slovenian flora, and contribution to the knowledge of the neophytic flora of Primorska region. Hladnikia, 25:31-43

Gray CP, Rawlins KA, Moorehead DJ, Bargeron CT, 2009. Invasive plants to watch for in Georgia. Tifton, Georgia, USA: Centre for Invasive Species and Ecosystem Health, The University of Georgia. http://www.gainvasives.org/handbook/EDRRplants.pdf

ISSG, 2012. Global Invasive Species Database (GISD). Global Invasive Species Database (GISD). Auckland, New Zealand: University of Auckland . http://www.issg.org/database

Janick, J., Paull, R. E., 2008. The encyclopedia of fruit & nuts, [ed. by Janick, J., Paull, R. E.]. Wallingford, UK: CABI.xviii + 954 pp. http://www.cabi.org/cabebooks/ebook/20113366221 doi:10.1079/9780851996387.0000

Kawagoe Suzuki TN, 2002. Floral sexual dimorphism and flower choice by pollinators in a nectarless monoecious vine Akebia quinata (Lardizabalaceae). Ecological Research, 17(3):295-303

Kofuji R, Ueda K, Yamaguchi K, Shimizu T, 1994. Molecular phylogeny in the Lardizabalaceae. Journal of Plant Research, 107(3):339-348

Li XYL, Zhong C, Chen X, Huang H, 2010. Akebia: a potential new fruit crop in China. HortScience, 45:4-10

Lindley J, 1847. Gardeners Chronicle and New Horticulturist. London, UK: Haymarket Publishing

Meehan T, 1887. The Gardeners' Monthly and Horticulturist - 201

Ministry for Primary Industries, 2014. National Pest Plant Accord. New Zealand. http://www.biosecurity.govt.nz/nppa

Missouri Botanical Garden, 2013. Tropicos database. St Louis, USA: Missouri Botanical Garden. http://www.tropicos.org/

Payne WW, Seago JL, 1968. The open conduplicate carpel of Akebia quinata (Berberidales: Lardizabalaceae). American Journal of Botany, 55(5):575-581

Pomeroy MM, 1873. Flower-Garden and Lawn. Pomeroy's Democrat. Chicago, Illinois, USA

Royal Horticultural Society, 2014. RHS Find a Plant website. London, UK: Royal Horticultural Society. https://www.rhs.org.uk/plants

Schweingruber FH, Börner A, Schulze ED, 2011. Atlas of stem anatomy in herbs, shrubs and trees: volume 1. Springer

Sonday R, Burnham RJ, 2014. Akebia quinata (Houtt.) Decne., USA: University of Michigan. http://www-personal.umich.edu/~rburnham/SpeciesAccountspdfs/AkebquinLARDFINAL.pdf

Swearingen JM, Reese A, Lyons RE, Williams CE, 2009. Fiveleaf akebia. Plant Conservation Alliance's Alien Plant Working Group. http://www.nps.gov/plants/alien/fact/akqu1.htm

USDA-ARS, 2013. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx

USDA-NRCS, 2013. Plants Database. USA: United States Department of Agriculture-Natural Resources Conservation Office. http://plants.usda.gov/java/

Watson L, Dallwitz MJ, 1992. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. The Families of Flowering Plants. http://delta-intkey.com

Zedaker Burch SMPL, 2001. Proceedings of the Southern Weed Science Society, 54th Annual meeting. Biloxi, Mississippi, USA

Zheng H, Wu Y, Ding J, Binion D, Fu W, Reardon R, 2006. Invasive plants of Asian origin established in the US and their natural enemies. Volume 1. Chinese Academy of Sciences and USDA Forest Service. http:\\www.us/foresthealth/technology/pdfs/IPAOv1ed2.pdf

Contributors

01/06/2014 Original text by:

John Peter Thompson, consultant, Upper Marlborough, Maryland, USA

Distribution Maps