Lupinus argenteus is a species of lupine known by the common name silvery lupine. It is native to much of western North America from the southwestern Canadian provinces to northernmost Mexico and as far east as the Great Plains. It grows in several types of habitats, including sagebrush, grassland, and forests.

Description Lupinus argenteus is a perennial plant with one or more stems that that usually grow tall, but occasionally can be as short as or as tall as . The stems branch towards their ends or have short spurs and are green or somewhat purple in color. They are covered with hairs that can be puberulent, fine short and erect, or strigose, straight and all pointing in the same direction. The stems grow from a root-crown at the surface of the soil or shallowly buried.

The leaves can appear green, ashy, or , nearly white in color, due to either being hairless or covered in hairs on their upper surface. Most of the leaves are cauline, attached to the stems of the plants. Each leaf is palmate, made up of leaflets radiating from a central attachment point, with six to nine leaflets for this species and attached by a petiole 1.5–8 cm long.

The flowers are in racemes that can be long, but more usually . They are either solitary at the end of stem or one larger one at the end of the stem with smaller racemes branching off below the primary, or several nearly equal in size. The flowers are typically blue-purple, but occasionally are lavender, pink, or white, but with a white or yellow spot on the uppermost banner petal that turns red-purple as the flower ages.

The fruit is a pod that is densely hairy containing two to six seeds and measuring 2–3 cm by 0.6–0.9 cm.

Taxonomy Lupinus argenteus was scientifically described by Frederick Traugott Pursh in 1813. It is part of the genus Lupinus in the family Fabaceae. He described it using specimens collected by Meriwether Lewis in an area he described as, "On the banks of the Kooskoosky River". This is now named the Clearwater River which forms the present day western Montana border with Idaho.

Varieties and subspecies There are two accepted subspecies and seven accepted botanical varieties of Lupinus argenteus. Each of these infraspecifics has one or more accepted synonyms.

Table of Synonyms Name Year Rank Synonym of: Notes Lupinus abiesicola 1944 species subsp. argenteus = het. Lupinus acclivatatis 1944 species subsp. argenteus = het. Lupinus achilleaphilus 1952 species subsp. argenteus = het. Lupinus adscendens 1903 species var. parviflorus = het. Lupinus alexanderae 1944 species subsp. argenteus = het. Lupinus alicanescens 1952 species subsp. argenteus = het. Lupinus aliumbellatus 1952 species subsp. argenteus = het. Lupinus allimicranthus 1942 species var. parviflorus = het. Lupinus alpestris 1899 species var. parviflorus = het. Lupinus alpestris var. argentatus 1940 variety subsp. argenteus = het. Lupinus alsophilus 1900 species subsp. argenteus = het. Lupinus alturasensis 1942 species subsp. argenteus = het. Lupinus annieae 1944 species subsp. argenteus = het. Lupinus argenteus f. albiflorus 1960 form subsp. argenteus = het. Lupinus argenteus subsp. ingratus 1972 subspecies var. fulvomaculatus = het. Lupinus argenteus subsp. moabensis 1978 subspecies var. moabensis = het., pro syn. Lupinus argenteus subsp. parviflorus 1955 subspecies var. parviflorus ≡ hom. Lupinus argenteus subsp. rubricaulis 1970 subspecies var. parviflorus ≡ hom. Lupinus argenteus var. argentatus 1989 variety subsp. argenteus = het. Lupinus argenteus var. aristatovatus 1940 variety subsp. argenteus = het. Lupinus argenteus var. boreus 1978 variety subsp. argenteus = het. Lupinus argenteus var. decumbens 1873 variety subsp. argenteus = het. Lupinus argenteus var. sericeus 1888 variety subsp. argenteus = het. Lupinus argenteus var. stenophyllus 1952 variety subsp. argenteus = het. Lupinus argenteus var. tenellus 1955 variety var. laxiflorus = het. Lupinus blankinshipii 1908 species var. parviflorus = het. Lupinus calcicola 1944 species subsp. argenteus = het. Lupinus candidissimus 1941 species var. palmeri = het. Lupinus capitis-amniculi 1946 species subsp. argenteus = het. Lupinus cariciformis 1946 species subsp. argenteus = het. Lupinus caudatus var. rubricaulis 1927 variety var. parviflorus ≡ hom. Lupinus charlestonensis 1944 species subsp. argenteus = het. Lupinus christianus 1946 species subsp. argenteus = het. Lupinus clarkensis 1944 species subsp. argenteus = het. Lupinus clokeyanus 1944 species var. palmeri = het. Lupinus corymbosus 1905 species subsp. argenteus = het. Lupinus davisianus 1942 species subsp. argenteus = het. Lupinus decumbens 1827 species subsp. argenteus = het. Lupinus decumbens var. argentatus 1906 variety subsp. argenteus = het. Lupinus edward-palmeri 1946 species subsp. argenteus = het. Lupinus equi-coeli 1946 species subsp. argenteus = het. Lupinus flavopinuum 1944 species subsp. argenteus = het. Lupinus floribundus 1892 species var. myrianthus = het. Lupinus foliosus 1847 species var. laxiflorus = het., nom. illeg. Lupinus fontis-batchelderi 1945 species var. palmeri = het. Lupinus fremontensis 1942 species subsp. argenteus = het. Lupinus fulvomaculatus 1915 species var. fulvomaculatus ≡ hom. Lupinus funstonanus 1945 species subsp. argenteus = het. Lupinus garrettianus 1949 species subsp. argenteus = het. Lupinus hendersonii 1940 species subsp. argenteus = het. Lupinus hullianus 1946 species var. laxiflorus = het. Lupinus ingratus 1900 species var. fulvomaculatus = het. Lupinus jaegeranus 1945 species var. palmeri = het. Lupinus jonesii 1905 species var. parviflorus = het., nom. illeg. Lupinus junipericola 1944 species var. palmeri = het. Lupinus keckianus 1945 species var. parviflorus = het. Lupinus lanatocarinus 1942 species subsp. argenteus = het. Lupinus lariversianus 1944 species subsp. argenteus = het. Lupinus laxiflorus 1828 species var. laxiflorus ≡ hom. Lupinus laxiflorus 1847 species subsp. argenteus = het., nom. illeg. Lupinus laxiflorus var. corymbosus 1936 variety subsp. argenteus = het. Lupinus laxiflorus var. foliosus 1840 variety subsp. argenteus = het. Lupinus laxiflorus var. tenellus 1840 variety var. laxiflorus = het. Lupinus laxus 1903 species var. parviflorus = het. Lupinus leptostachyus 1901 species var. myrianthus = het. Lupinus lucidulus 1902 species subsp. argenteus = het. Lupinus merrillanus 1946 species subsp. argenteus = het. Lupinus mexicanus 1853 species subsp. argenteus = het., nom. illeg. Lupinus montis-cookii 1952 species var. laxiflorus = het. Lupinus myrianthus 1900 species var. myrianthus ≡ hom. Lupinus olive-brownae 1948 species subsp. argenteus = het. Lupinus olive-nortonae 1948 species subsp. argenteus = het. Lupinus ornatus 1858 species subsp. argenteus = het., nom. illeg. Lupinus palmeri 1873 species var. palmeri ≡ hom. Lupinus palmeri var. clawsonianus 1939 variety var. palmeri = het. Lupinus palmeri var. humilis 1939 variety var. palmeri = het. Lupinus parviflorus 1838 species var. parviflorus ≡ hom. Lupinus parviflorus subsp. floribundus 1972 subspecies var. myrianthus = het. Lupinus parviflorus subsp. myrianthus 1972 subspecies var. myrianthus ≡ hom. Lupinus parviflorus var. complicatus 1891 variety subsp. argenteus = het. Lupinus parviflorus var. fulvomaculatus 1972 variety var. fulvomaculatus ≡ hom. Lupinus patulipes 1944 species subsp. argenteus = het. Lupinus populorum 1944 species subsp. argenteus = het. Lupinus portae-westgardiae 1945 species var. palmeri = het. Lupinus pulcher 1942 species subsp. argenteus = het. Lupinus pulcherrimus 1903 species var. parviflorus = het. Lupinus rubricaulis 1901 species var. parviflorus ≡ hom. Lupinus seclusus 1946 species var. parviflorus = het. Lupinus serradentum 1946 species var. parviflorus = het. Lupinus sicco-silvae 1944 species subsp. argenteus = het. Lupinus sitgreavesii 1873 species subsp. argenteus = het. Lupinus spathulatus 1902 species subsp. argenteus ≡ hom. Lupinus spathulatus var. boreus 1952 variety subsp. argenteus = het. Lupinus standingii 1952 species subsp. argenteus = het. Lupinus stenophyllus 1907 species subsp. argenteus = het. Lupinus sublanatus 1942 species subsp. argenteus = het. Lupinus summae 1946 species subsp. argenteus = het. Lupinus tenellus 1832 species var. laxiflorus = het. Lupinus trainianus 1944 species subsp. argenteus = het. Notes: ≡ homotypic synonym; = heterotypic synonym

Names The species name, argenteus, means silvery and its common name is silvery lupine.

Range and habitat Silver lupins grow throughout the western United States, parts of western Canada, and two states in Mexico. In Canada it grows in the provinces of British Columbia, Alberta, and Saskatchewan. In the Pacific Northwest it is native to the eastern portions of Washington and Oregon as well as almost all of Idaho. To the east the species grows throughout the Rocky Mountains in the states of Montana and Wyoming and onto the Northern Great Plains as far as western North Dakota and South Dakota. South of this they are mostly found in the Nebraska panhandle and all but the most eastern portions of Colorado. It may also be native to Kansas, but there is not specific location to the records and it is not listed in the Flora of the Great Plains as occurring in Kansas. In Mexico it grows in the northwest in Chihuahua and Sonora.

It grows in a wide range of plant communities including with ephedra, in grasslands, sagebrush steppes, piñon–juniper woodlands, ponderosa pine forests, aspen groves, and even with spruce-fir communities.

Ecology Many butterflies use silvery lupins as a food plant while caterpillars including the arrowhead blue (Glaucopsyche piasus), gray hairstreak (Strymon melinus), lupine blue (Icaricia icarioides), and silvery blue (Glaucopsyche lygdamus). It is an alternate food plant for the caterpillars of the hops azure butterfly (Celastrina humulus).

References Citations

Sources Books

Web sources

External links

Jepson eFlora Treatment