|Photo by Wayne Matchett, SpaceCoastWildflowers.com|
|Division:||Magnoliophyta - Flowering plants|
|Class:||Magnoliopsida – Dicotyledons|
|Family:||Fabaceae ⁄ Leguminosae|
| Lupinus diffusus|
|Natural range of Lupinus diffusus from USDA NRCS Plants Database.|
Common names: Oak Ridge lupine, Skyblue lupine
"Annual, biennial, or perennial herbs, rarely shrubs. Leaves palmately compound with (3) 5-15 (18) leaflets or 1-foliolate and then appearing simple; stipules partly adnate to the petiole, often caduceus. Racemes terminal with pedicellate, papilionaceous flowers subtended by usually caduceus bracts. Calyx conspicuously 2-lipped with the lips entire to deeply lobed; corolla commonly blue, white or yellow, rarely purplish, standard broadly obovate to orbicular and typically with reflexed margins; stamens monadelphous, filaments o two lengths, the longer with globose, versatile anthers, the shorter with linear, basifixed anthers; ovary sessile. Legume oblong, flattened, 2-12 seeded." 
"Cespitose herb perennating, decumbent stems 2-4 dm or more long from a woody taproot; more or less densely short-pubescent throughout. Leaves 1-foliolate, evergreen, mostly oblong to elliptic, 4-12 cm long, 1.5-5 cm wide; petiole 3-10 cm long; stipules fused to petiole for (0.3) 0.8-2 (3) cm , free portion filiform, 0.5-2.5 cm long. Racemes 1-3 dm long; pedicels 1-4 mm long, each subtended by a caduceus, subulate bract 4-8 mm long, the lower 3-lobed with the 2 laterals linear and ca. 2 mm long and the central 5-7 mm long; petals light to deep blue, the standard with a conspicuous cream spot. Legume linear-oblong, 3-4.5 cm long, 7-9 mm broad, appressed-pubescent with trichomes ca. 2 mm long.' 
It is distributed through out the southeast, from Mississippi through North Carolina.
In the Coastal Plain in Florida, L. diffusus can occur in longleaf pine-scrub oak sand ridges, sand pine scrubs, deciduous scrub oak barrens, sand pine woods, and live oak-palmetto scrubs. Associated species include Carya floridana, Lechea, Chamaecyparis, Quercus virginiana, Q. laevis and Q. incant. 
Like many other legumes, L. diffusus has root nodules that contain nitrogen fixing bacteria that provide the plant with nitrogen, even in poor soils.
Seeds are dispersed by wind and animals.
Responds quickly to soil disturbance and fire.
The following Hymenoptera families and species were observed visiting flowers of Lupinus diffusus at Archbold Biological Station: 
Apidae: Bombus griseocollis
Megachilidae: Anthidiellum notatum rufomaculatum, A. perplexum, Megachile exilis parexilis
Use by animals
Conservation and management
Cultivation and restoration
Flowers of Lupinus diffusus
Photo by Wayne Matchett, SpaceCoastWildflowers.com
References and notes
- Radford, Albert E., Harry E. Ahles, and C. Ritchie Bell. Manual of the Vascular Flora of the Carolinas. 1964, 1968. The University of North Carolina Press. 586-7. Print.
- [] NatureServe Accessed: February 8, 2016
- Florida State University Robert K. Godfrey Herbarium database. URL: http://herbarium.bio.fsu.edu. Last accessed: October 2015. Collectors: Loran C. Anderson, J. Beckner, D. Burch, George R. Cooley, A.H. Curtiss, H.A. Davis, R.K. Godfrey, M. Hopkins, Ann F. Johnson, Beverly Judd, Walet Judd, Edwin Keppner, R. Kral, O. Lakela, Robert J. Lemaire, Fred L. Lewton, Sidney McDaniel, Grady W. Reinert, Paul O. Schallert, D.B. Ward, Kenneth A. Wilson, Carroll E. Wood, Jean Wooten. States and Counties: Florida: Brevard, Clay, Citrus, Coffee, Hernando, Highlands, Hillsborough, Lake, Levy, Marion, Okaloosa, Osceola, Polk, Santa Rosa, Seminole, Walton, Washington. Compiled by Tall Timbers Research Station and Land Conservancy.
- [] UNF Landscape Accessed: February 9, 2016
- Nelson, G. PanFlora: Plant data for the eastern United States with emphasis on the Southeastern Coastal Plains, Florida, and the Florida Panhandle. www.gilnelson.com/PanFlora/ Accessed: 12 DEC 2016
- [] Dave's Garden Accessed: February 9, 2016
- [] Accessed: February 9, 2016
- Deyrup, M.A. and N.D. 2015. Database of observations of Hymenoptera visitations to flowers of plants on Archbold Biological Station, Florida, USA.