Lupinus polyphyllus (large-leaved lupin)
Large-leaved lupin is one of the most spectacular perennial lupins native to western North America.
Lupinus polyphyllus (Photo: Wikimedia Commons, licensed under CC by 3.0)
Lupinus polyphyllus Lindl.
large-leaved lupin, garden lupin (UK); bigleaf lupine, meadow lupine, blue pod (USA)
Not assessed according to IUCN Red List criteria but not considered to be threatened.
On moist, generally well-drained soils; in mesic mountain forests, meadows, sage brush and pine forests, often on riversides.
Ornamental, fodder, green manure.
Ingestion of any part of a Lupinus can cause gastrointestinal upset or more severe symptoms if large quantities are consumed.
About this species
Lupinus polyphyllus was introduced to Europe from North America by the famous explorer and plant collector David Douglas. Formerly widely grown as a striking garden plant in its own right, L. polyphyllus is one of the parents in crosses that formed the renowned Russell Hybrids, Lupinus × regalis, which became a popular garden ornamental in the UK from the late 1930s onwards.
The genus takes its name from the Latin lupus, meaning wolfish, in reference to the mistaken belief that this plant devours nutrients from the soil. A member of the pea and bean family (Leguminosae), large-leaved lupin can actually enhance soil fertility with the help of nitrogen-fixing bacteria within special root nodules.
Geography and distribution
Large-leaved lupin is native to western North America (from the Pacific States east to the Rocky Mountains in the USA and north to British Columbia in Canada), where it is found from sea level to 2,200 m (occasionally to 2,600 m) above sea level. It has also been introduced to parts of Europe, eastern Canada and New Zealand, and in the last it is considered to be an important invasive species. In parts of Europe, the species is locally naturalised, and spontaneous hybrids with Lupinus ×regalis (in cultivation known as Russell hybrids) and other introduced species including L. nootkatensis (Nootka lupin), have been reported.
A stout herbaceous perennial, large-leaved lupin grows up to 1.5 m tall. The palmate leaves are divided into 9–17 leaflets; leaflets are up to 15×3 cm. Flowers can be blue, purple, pink or white and are up to 14 mm long. The pea-like flowers are arranged densely on stems up to 60 cm long. The fruit is a brown pod up to 4 cm long, covered with matted, woolly hairs; the pod opens to release 5–9 spotted seeds.
In addition to this general description of large-leaved lupin, it is important to note that the external form and appearance of this species is highly variable across its wide range in western North America.
How many species?
Lupinus polyphyllus, as currently circumscribed by Barneby (1989) and Isely (1998), comprises a set of six named botanical varieties, occupying distinct but somewhat overlapping distributions. These are L. polyphyllus var. ammophilus, L. polyphyllus var. burkei, L. polyphyllus var. humicola, L. polyphyllus var. polyphyllus, L. polyphyllus var. prunophilus and L. polyphyllus var. saxosus, although some authors still maintain these as distinct species (Riggins & Sholars, 1993).
Threats and conservation
This species is widespread and often locally abundant, and is not considered to be threatened.
Formerly a popular garden plant, particularly in Europe, large-leaved lupin is an attractive addition to flower borders and cottage gardens and went on to be used as one of the parents of the famous Russell Hybrids that have dominated lupin-growing since the 1930s.
Lupinus species are variably toxic due to the presence of alkaloids such as quinolizidine, and ingestion of foliage of some species can be fatal. Despite toxicity of some Lupinus species, others (L. albus, L. luteus and L. mutabilis) are cultivated for their edible, high protein seeds. Large-leaved lupin has been cultivated as a fodder crop and green manure, for example in Belarus and Ukraine.
Low alkaloid forms of Lupinus polyphyllus have recently been produced, and the commercial cultivar L. polyphyllus ‘Pervenec’ has been released; L. polyphyllus is of particular value in northern regions of the world such as Finland and Russia, where seeds of other Lupinus species do not ripen.
Millennium Seed Bank: Saving seeds
The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
Five collections of Lupinus polyphyllus are held in Kew’s Millennium Seed Bank based at Wakehurst in West Sussex.
This species at Kew
Pressed and dried specimens of Lupinus polyphyllus are held in Kew’s Herbarium, where they are available to researchers by appointment.
Kew at the British Museum – North American Landscape
Large-leaved lupin (Lupinus polyphyllus) was one of the 12 star plants featured in the 2012 North American Landscape - the fifth in the series created by Kew for the British Museum’s West Lawn.
North American plants have global ecological and economic importance and have been utilised by native peoples for thousands of years. Many were introduced to Europe following the colonisation of North America in the early 1600s. Grown for their medicinal uses, as food crops and for other economic purposes, some species have also become familiar ornamental garden plants.
The landscape was designed to evolve throughout the seasons - from a carpet of colourful daisies in the summer to spectacular orange and red maple leaves in the autumn. Other plantings included cypress, echinacea and carnivorous pitcher plants.
Barneby, R.C. (1989). Intermountain Flora. Vascular Plants of the Intermountain West, USA. Vol. 3B. Fabales. New York Botanical Garden.
Dauncey, E. A. (2010). Poisonous Plants. Royal Botanic Gardens, Kew.
Huxley, A., Griffiths, M. & Levy, M. (eds) (1997). The New Royal Horticultural Society Dictionary of Gardening. Volume 3 (L to Q). Macmillan Reference, London.
Image: 'Lupinus polyphyllus'. Licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Available online.
Isely, D. (1998). Native and Naturalized Leguminosae of the United States. Monte L. Bean Life Science Museum, Brigham Young University, Provo, USA.
Kurlovich, B.S. (ed.) (2002). Lupins (Geography, Classification, Genetic Resources and Breeding). OY International North Express, St Petersburg, Russia.
Lewis, G., Schrire, B., Mackinder, B. & Lock, M. (2005). Legumes of the World. Royal Botanic Gardens, Kew.
Mabberley, D. J. (2008). Mabberley’s Plant-book: a Portable Dictionary of Plants, their Classification and Uses. Third edition. Cambridge University Press, Cambridge.
Riggins, R. & Sholars, T. (1993). Lupinus. In: The Jepson Manual of Higher Plants of California, ed. J.C. Hickman. University of California Press.
The Plant List (2010). Lupinus polyphyllus. Available online (accessed 16 April 2012).
Kew Science Editor: Colin Hughes and Emma Tredwell
Copyediting: Emma Tredwell
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