''Lupinus arboreus'', the yellow bush lupine (US) or tree lupin (UK), is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the legume

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Fabaceae.

Description

''Lupinus arboreus'' is an

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

shrub growing to tall (hence the alternative common name, tree lupine) in sheltered situations, but more typically tall. It is capable of tolerating temperatures down to −12 °C and living for up to seven years. It has green to gray-green palmate leaves, with 5–12 leaflets per leaf. The leaflets are long, often sparsely covered with fine silky hairs. In spring it bears many

racemes A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the s ...

, long, of fragrant, soft yellow, pea-like flowers. Both yellow and lilac to purple flowering forms are known. However, the yellow form is more common, except in the north of the species' range.

Distribution

The shrub is

indigenous Indigenous may refer to: *Indigenous peoples *Indigenous (ecology), presence in a region as the result of only natural processes, with no human intervention *Indigenous (band), an American blues-rock band *Indigenous (horse), a Hong Kong racehorse ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, US,Jepson: ''Lupinus arboreus''
/ref> where it is widely distributed among

coastal sage scrub Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is ...

and sand dunes. Because it has been widely introduced in the state, there is some uncertainty about its native range. It is thought to be native from

Point Reyes National Seashore Point Reyes National Seashore is a park preserve located on the Point Reyes Peninsula in Marin County, California. As a national seashore, it is maintained by the US National Park Service as an important nature preserve. Some existing agricult ...

south to

San Luis Obispo County San Luis Obispo County (), officially the County of San Luis Obispo, is a county on the Central Coast of California. As of the 2020 census, the population was 282,424. The county seat is San Luis Obispo. Junípero Serra founded the Miss ...

Invasive species

It has escaped from cultivation to become an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

in many areas. Outside of its native range in central and northern coastal California, it can become invasive southwards in

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...

and

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

, and northwards in the coastal

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

and

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

. It is an

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

western Europe Western Europe is the western region of Europe. The region's countries and territories vary depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

(a potential noxious weed),

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

, the Turkish Anatolian Aegean Region, and

southern South America The Southern Cone ( es, Cono Sur, pt, Cone Sul) is a geographical and cultural subregion composed of the southernmost areas of South America, mostly south of the Tropic of Capricorn. Traditionally, it covers Argentina, Chile, and Uruguay, bou ...

including the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...

. Like many members of the Fabaceae, it is an effective fixer of nitrogen in the soil. Where it has been introduced, it changes the chemistry of the soil, and therefore allows other exotics to establish themselves, to the detriment of

native plant In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equ ...

s adapted to low nitrogen levels. It also hybridizes with other lupine species outside its range, such as ''

Lupinus littoralis ''Lupinus littoralis'' is a species of lupine known by the common name seashore lupine. It is native to the coastline of western North America from British Columbia to northern California, where it grows in sandy habitat. It is a low perennial h ...

'' (seashore lupin) and ''

Lupinus rivularis ''Lupinus rivularis'' is a species of lupine known by the common name riverbank lupine native to North America. It is also commonly known as river lupine, streambank lupine, and stream lupine.Darris, D.; Young-Mathews, A. Plant Fact Sheet for Ri ...

'' (riverbank lupin), further endangering the survival of those native ecosystem integrated species.

Cultivation

The yellow-flowering form of ''Lupinus arboreus'' is widely grown as an

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

, for its attractive flowers in traditional,

, and

wildlife garden A wildlife garden (or wild garden) is an environment created by a gardener that serves as a sustainable haven for surrounding wildlife. Wildlife gardens contain a variety of habitats that cater to native and local plants, birds, amphibian ...

s. It is also used to bind drifting sand dunes. It can be seen growing in cracks in vertical stone walls, due to the sharp drainage. Lupins can also be cultivated on balconies or patios in pots. It has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

Related shrub species

In addition to the numerous annual and perennial lupines, some other Lupine species also naturally grow as

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

s, including:Koti.mbnet.fi: Classification of Lupins
*''

Lupinus chamissonis ''Lupinus chamissonis'' is a species of lupine known by the common name Chamisso bush lupine. It is endemic to California, where it is known from most of the length of the coastline. It grows in sand dunes and other immediate coastal habitat. ...

'' — Chamisso bush lupine, silver bush lupine *''

Lupinus albifrons ''Lupinus albifrons'', silver lupine, white-leaf bush lupine, or evergreen lupine, is a species of lupine (lupin). It is native to California and Oregon, where it grows along the coast and in dry and open meadows, prairies and forest clearings. ...

'' — Bush lupine *''

Lupinus excubitus ''Lupinus excubitus'' is a species of lupine known as the grape soda lupine. Its common name refers to its sweet scent, which is said to be very reminiscent of grape soda. This species and its variants are found in Southwestern United States, e ...

'' — Grape soda lupine *''

Lupinus longifolius ''Lupinus longifolius'' is a species of lupine known by the common name longleaf bush lupine. It is native to the coastal mountain ranges and hillsides of southern California and Baja California, where it grows in local habitat in the canyons an ...

'' — Longleaf bush lupine

References

External links

Calflora Database: ''Lupinus arboreus'' (yellow bush lupine, coastal bush lupine)

Jepson Manual eFlora (TJM2) treatment of ''Lupinus arboreus''
{{Taxonbar, from=Q4117740 arboreus Endemic flora of California Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Natural history of the Channel Islands of California Natural history of the San Francisco Bay Area Garden plants of North America Drought-tolerant plants Flora without expected TNC conservation status