Lupinus angustifolius

Fabaceae. Annual native to the Mediterranean basin, naturally present from the Iberian Peninsula to Asia Minor, and widely naturalized outside this area. It colonizes dry lawns, wastelands, roadsides, and poor sandy or stony soils, always in full sun and on well-drained, acidic to neutral soils.

The plant is upright to slightly spreading, reaching 20 to 60 cm in height depending on conditions. Its most immediately distinctive feature is its palmate foliage with very narrow and linear leaflets, of a glaucous green, giving it a fine and airy texture very different from other Mediterranean annual lupins. The stems and leaves bear a silvery silky pubescence, clearly visible in sunny weather.

The flowers, gathered in rather loose terminal spikes, are bright blue to true blue-violet, sometimes slightly bicolored with a paler banner. In its natural habitat, it blooms from April to June.

Like other lupins, this species fixes atmospheric nitrogen through its root nodules, thus improving the poor soils it colonizes. It has also been cultivated as a fodder plant and green manure. In gardens, it is sown in place in the spring on light and draining soil, in sunny naturalistic compositions; it readily reseeds itself from year to year.