Miniature Lupine

Bicolor Lupine
Lupinus bicolor
NATIVE

Description (Jepson, PlantID.net)

• Eudicotyledon
  • Eudicots are a major lineage of flowering plants; see family for general characteristics
• Pea Family (Fabaceae)
• Annual herb (may live 2 seasons in some areas)
• Stems are short and hairy (pubescent)
• Leaves
  • Palmately compound (separate leaflets radiating from a single point)
  • 5-7 narrow leaflets
  • Hairy
• Flowers
  • Inflorescence (flower arrangement) is a raceme (unbranched stem with stalked flowers opening from the bottom up)
  • Arranged in whorls (3 or more leaves/flowers at each junction with stem)
  • Characteristic Pea family flower is bilaterally-symmetric, with a banner, wings, and keel
    • Banner is blue with a white center, sometimes with small black spots
      • With aging or pollination, white center turns magenta
    • Wings are blue
    • Keel is white
  • Ovary superior (above the attachment of other flower parts)
• Fruit is a thin, short, hairy legume (a single-chambered seed pod that opens along 2 seams), up to 1 in. long
• Height to 16 in.

Distribution

• Native to California
  • Grows in a variety of habitats including coastal scrub, conifer forests, mixed evergreen forests, foothill woodlands, and grasslands
  • See Calflora for statewide observations of this plant
• Outside California, grows from British Columbia to Baja California, Mexico
• Grows at elevations to 5,250 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

• Wildlife
  • Frequented by bumblebees and other native bees
  • Authorities differ on the production of nectar in lupines, perhaps because nectar production may differ by species; see Ayers (2016) for a summary of the controversy
  • Larval food source (host) for several butterfly species, e.g. silvery blue (Glaucopsyche lygdamus), painted lady (Vanessa carduii), and acmon blue (Plebejus acmon)
• Native people
  • Greens eaten after boiling to remove toxic alkaloids and protease inhibitors (Anderson 2005)
• CAUTION – Lupines contain varying amounts of toxic alkaloids
  • Bitter taste deters herbivores
  • Some species are poisonous to livestock and humans

Name Derivation

• Lupinus (loo-PIE-nus) – from the Latin for “wolf,” for uncertain reasons
  • Perhaps because lupine species with high alkoloid levels can, like wolves, harm livestock and humans (Kurlovich 2006)
    • Lupines with low alkoloid levels make excellent livestock feed
  • Perhaps because it was mistakenly believed that lupines depleted the soil of nutrients (Merriam-Webster 2024)
    • This seems unlikely, however, as farmers since ancient times have known that lupines, as members of the Pea family, make soils more fertile by adding nitrogen (Kurlovich 2006)
  • Perhaps from the tendency of some lupines to overrun ground (Jepson)
• bicolor (BYE-kol-or) – from the prefix bi-, “two,” and “color,” referring to 2 colors of the flower
• Miniature lupine – refers to its diminutive size relative to most lupine species

Notes

• Miniature lupines often grow in large patches that sweep across open, sunny areas, making a bright, contrasting background for orange poppies (Eschscholzia californica), pink owl’s clovers (Castilleja species), and other spring wildflowers
• Like almost all members of its family, miniature lupine fixes nitrogen; see Pea family for more details
• Banner spot of lupine flowers changes color as the flower ages (Stead and Reid 1990)
  • This change occurs more quickly after pollination
  • Even though the flower shows no sign of wilting, color change tells visiting insects to move on to another flower
  • These unwilted, pollinated flowers remain to help attract pollinators from a distance
  • Flowers from more than 70 plant families use color changes to direct pollinators (Weiss 1991)
• Jepson notes that Lupinus bicolor is highly variable, with many subspecies and varieties indistinct in form and distribution
• Edgewood has 7 lupine species, a remarkable number for a relatively small preserve and an indication of Edgewood’s species diversity

ID Tips

• Flowers and leaves of lupines are characteristically similar
• Miniature lupine is the only lupine at Edgewood that makes carpets of color in the grasslands and is generally smaller than the others
• May be confused with the 6 other lupine species at Edgewood
  • Sky lupine (L. nanus)
  • Fleshy lupine (L. affinis)
  • Chick lupine (L. microcarpus var. densiflorus)
  • Summer lupine (L. formosus var. formosus)
  • Arroyo lupine (L. succulentus)
  • Silver bush lupine (L. albifrons var. albifrons)

	Miniature Lupine	Sky Lupine	Fleshy Lupine	Chick Lupine	Summer Lupine	Arroyo Lupine	Silver Bush Lupine
Growth Habit	annual	annual	annual	annual	perennial herb	annual; can appear a perennial herb	woody shrub
Height	≤ 16 in.	≤ 24 in.	≤ 20 in.	≤ 31 in.	≤ 31 in.	≤ 39 in.	≤ 16 ft., usually 3-5 ft.
Hairiness	hairy	hairy	hairy	sparsely to densely hairy	densely hairy	fleshy, sparsely hairy	silver-hairy
Leaflet Tip	sharply pointed	pointed	rounded or pointed	pointed	sharply pointed	wide, blunt	pointed
Inflorescence Length	≤ 3 in.	≤ 16 in.	≤ 8 in.	≤ 12 in., often in distinct tiers	≤ 12 in.	≤ 6 in.	≤ 12 in.
Flower Color	blue ⋯ banner spot white > magenta	blue ⋯ banner spot white > magenta	blue-purple ⋯ banner spot white > magenta	white to yellow; rose to purple ⋯ no banner spot	faded blue-purple ⋯ banner spot white or none	blue-purple ⋯ banner spot white > magenta	blue-purple ⋯ banner spot white to yellow > magenta
Fruit Arrangement	encircle stem	encircle stem	encircle stem	cluster to 1 side	encircle stem	encircle stem	encircle stem
Best Trails	Ridgeview, Sunset, Edgewood	Lower Clarkia	Lower Clarkia	Native Garden, Upper Sylvan	Upper Edgewood	Upper Sylvan	all trails

At Edgewood

• Found in grasslands
  • See iNaturalist for observations of this plant
• Flowers March – May

Specific References

Anderson, M.K. 2005. Tending the Wild. University of California, Berkeley. Pp. 274.

Ayers, G. 2016, Oct. 1. The controversy over nectar production. Introduction to genus Lupinus. American Bee Journal.

Elpel, T.J. 2013. Pea family – Fabaceae [Illustration of pea subfamily, adapted]. Botany in a Day: The Patterns Method of Plant Identification. HOPS Press, Pony, Montana.

Kurlovich, B.S. 2006, July 17. The history of lupin domestication. Blog. Lupins.

Lady Bird Johnson Wildflower Center. 2018. Lupinus bicolor. Plant Database. University of Texas at Austin.

Merriam-Webster.com Dictionary. 2024. Lupine. Merriam-Webster.

Stead, A.D., and M.S. Reid. 1990. The effect of pollination and ethylene on the colour change of the banner spot of Lupinus albifrons (Bentham) flowers. Annals of Botany 66: 655-663. Postharvest Center. Department of Plant Sciences, College of Agriculture and Environmental Sciences, University of California, Davis, and University of California Agriculture and Natural Resources (UC ANR).

Weiss, M. 1991, Nov. 21. Floral colour changes as cues for pollinators. Nature 354: 227-229.

General References

Calflora Database. 2014. Berkeley, California.

Calscape. 2018. California Native Plant Society.

Charters, M.L. 2015. California Plant Names: Latin and Greek Meanings and Derivations.

Charters, M.L. 2017. Southern California Wildflowers: Guide to the Pronunciation of Specific, Generic and Family Names.

Corelli, T. 2004. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California.

Dave’s Garden.

Elpel, T.J. 2013. Botany in a Day: The Patterns Method of Plant Identification. HOPS Press, Pony, Montana.

Flora of North America. efloras.org.

Harris, J.G., and M.W. Harris. 2013. Plant Identification Terminology: An Illustrated Glossary. Spring Lake Publishing, Spring Lake, Utah.

Keator, G. 2009. California Plant Families. University of California Press, Berkeley and Los Angeles, California.

Native American Ethnobotany DB.

Regents of the University of California. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.