Lupin (Lupinus): botany, uses, distribution, and notable species
Lupin (or lupine) is the common name for Lupinus, a diverse genus of flowering legumes. This article covers their appearance, distribution, ecology, cultivation, uses and notable facts.
Overview. Lupin, often spelled lupine in North America, is the common name for plants of the genus Lupinus, which belongs to the legume family Fabaceae. The genus contains roughly 150–200 species and is valued for its distinctive flowers, nutrient-rich seeds, and ability to improve soil fertility.
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Botanical characteristics
Members of Lupinus vary from small annual herbs to long-lived perennials and occasionally shrubs or trees. Typical features include palmately divided leaves with 5–17 leaflets, often soft green or silvery and sometimes densely hairy. The inflorescence is a vertical spike of pea-like flowers with an upper standard, two lateral wings and a lower fused keel. Fruits are pods that contain several seeds; these seeds range in size and composition between species.
Distribution and taxonomy
Lupins have a broad natural range. Many species are native to the Mediterranean region and adjacent areas of Europe and North Africa, including taxa placed in the subgenus Lupinus (Old World). A large radiation of species occurs in the Americas, grouped in subgenus Platycarpos and related sections, with diverse forms from the western United States to South America. Several species are adapted to mountain or coastal habitats and some have colonized disturbed soils.
Growth form and notable sizes
Most lupins are herbaceous perennials 0.3–1.5 m tall, though some are annuals and a few take a woody guise: certain shrubs reach up to 3 m, and rare species may be tree-like in habit. Individual species differ in leaf hairiness, leaflet number and flower color, producing whites, yellows, pinks, purples and deep blues in cultivation and the wild. See individual species pages for precise measurements and forms represented in regional floras.
Uses, cultivation and examples
- Horticulture: many lupins are grown as ornamental plants for their tall, colorful flower spikes and foliage (e.g., garden hybrids).
- Agriculture: some species are used as green manure and cover crops for their nitrogen-fixing roots; certain lupin seeds are used as high-protein foodstuffs after processing.
- Regional foods: in parts of the Mediterranean and South America, processed lupin beans are a traditional snack or ingredient.
- Notable examples include spring-blooming native species such as regional bluebonnets and widely planted garden lupins.
For further cultivation advice and regional varieties consult dedicated horticultural resources: American flora, growth guides, and seed suppliers or botanical references linked below.
Ecology, safety and notable facts
Lupins form symbiotic relationships with nitrogen-fixing bacteria, improving soil fertility and often colonizing poor or disturbed soils. While many species are beneficial, some contain bitter alkaloids that require leaching or breeding for low-alkaloid forms before consumption. Allergies to lupin proteins have been reported and are treated as food allergens in some jurisdictions. Several lupins are important nectar sources for bees and other pollinators.
Further reading and resources: taxonomic databases and conservation assessments provide species lists and distribution maps. Explore links about spelling and common names (nomenclature), legume family context (Fabaceae overview), leaf and flower morphology (leaf form, flower structure), seed and pod characteristics (pod anatomy, seed uses), and agronomic notes (cultivation, food safety).
Description
The species are mostly herbaceous perennials 0.3-1.5 meters tall, some annuals and others tree-like shrubs up to 4.5 meters tall. An exception is the Chamis de Monte (Lupinus jaimehintoniana) of Oaxaca in Mexico, which grows up to 8 m tall. They usually form a taproot.
Lupines usually have long-stalked and soft, green to gray-green leaves that are often densely covered with silvery hairs. Leaf blades are usually palmately divided and subdivided into five to 28 entire marginal fingers, or reduced to a single leaf in some species in the southeastern United States. Stipules are often present.
The flowers are in dense or open, erect, terminal racemes or spikes. Each flower with double perianth is about 1-2 cm long. Bracts and/or bracteoles may be present. The calyx is often two-lipped. The hermaphrodite, blue, purple, red, pink, yellow, orange, white, or mixed-colored butterfly flowers have an upper flag, two lateral wings, and two lower petals fused into a keel. There are 10 stamens, either diadelphous (with 9 usually fused) or monadelphous and some unequal in length (5 + 5; with dimorphic anthers). The elongate ovary is superior, with a long, curved style and a small cephalic stigma. The fruit is a legume containing several, roundish and flattened, rough to smooth seeds.
The chromosome number is 2n = 36, 42, 48 or 96.
Systematics
The genus Lupines (Lupinus) is divided into two subgenera. Depending on the author, there are one hundred to several hundred species. Here is a selection:
- Subgenus Lupinus (Syn.: Lupinus subgen. Eulupinus Aschers. et Graebn. ):
- White lupine (Lupinus albus L. ): It grows preferentially on sandy, calcareous loam and loess soils and is native to the Balkan Peninsula, the Aegean and Turkey.
- Blue lupin or narrow-leaved lupin (Lupinus angustifolius L. ): Prefers sandy loam soils and is native to southern Europe, North Africa and the Near East.
- Lupinus micranthus Guss. The native country is Southern Europe, North Africa and Near East.
- Yellow lupine (Lupinus luteus L. ): Prefers sandy, lime-free soils. Its home is Portugal, Spain and the Aegean.
- Lupinus hispanicus Boiss. et Reut. It occurs in Portugal and in Spain.
- Lupinus cosentinii Guss. It occurs in Portugal, Spain, Italy, Corsica, Sardinia, Sicily, Morocco and Tunisia.
- Lupinus digitatus Forssk. It is found in Morocco, Algeria and Egypt.
- Lupinus princei Harms: It occurs in tropical Africa.
- Lupinus pilosus L. : It occurs in Greece, in the Aegean Sea and in the Near East.
- Lupinus palaestinus Boiss. It occurs in Jordan, Israel and the Sinai Peninsula.
- Lupinus atlanticus Gladst. : It occurs in Morocco.
- Subgenus Platycarpos (S. Watson) Kurl. : The legumes are mostly flat. They have natural occurrences only in the New World. With several hundred species (selection):
· 
Yellow lupin (Lupinus luteus)
· 
Polyphyllous lupine (Lupinus polyphyllus)
· 
Blue lupin (Lupinus angustifolius)
· 
Alaskan lupine (Lupinus nootkatensis)
Questions and answers
Q: What is lupin?
A: Lupin, also spelled lupine in North America, is a common name for members of the genus Lupinus in the family Fabaceae.
Q: How many species of lupin are there?
A: The genus Lupinus includes between 150-200 species.
Q: Where are lupins distributed across the world?
A: Lupins have a wide distribution in the Mediterranean region - Subgen. Lupinus, and the Americas - Subgen. Platycarpos (Wats.) Kurl.
Q: What are the characteristics of lupin species?
A: The species are mostly herbaceous perennial plants 0.3-1.5 m tall, but some are annual plants and a few are shrubs up to 3 m tall. They have soft green to grey-green or silvery leaves with the blades usually palmately divided into 5–17 leaflets or reduced to a single leaflet in a few species of the southeastern United States. In many species, the leaves are hairy with silvery hairs, often densely so.
Q: What do lupin flowers look like?
A: The flowers are produced in dense or open whorls on an erect spike, each flower 1-2 cm long, with a typical peaflower shape with an upper 'standard', two lateral 'wings' and two lower petals fused as a 'keel'.
Q: What is the fruit of the lupin plant?
A: The fruit is a pod containing several seeds.
Q: Is there a lupin species that can grow into a tree?
A: Yes, Lupinus jaimehintoniana is a lupin species that can grow into a tree up to 8 m high with a trunk 20 cm in diameter, from the Mexican state of Oaxaca.
Related articles
Author
AlegsaOnline.com Lupin (Lupinus): botany, uses, distribution, and notable species Leandro Alegsa
URL: https://en.alegsaonline.com/art/59960
Sources
- personal.inet.fi : Classifications