Coulter's Lupine
Lupinus sparsiflorus
Photographed in Maricopa County, Arizona, USA, March 2008. Notice also that there is an irridescent, blue-green, Blister Beetle (Meloidae, Lytta) on the flowers.
ANNUAL: Ephemeral herb of the Sonoran Desert spring. Blooming by mid
spring (Feb.) in years with adequate rainfall. Absent in drought years. Most
plants less than ½ meter tall.
Grows erect.
FLOWERS: Dark blue-purple pea flowers sometimes with the wing petals,
hood or entire flower tinged with pink and white. The flowers appear on a
verticle spike and open mostly February to April.
LEAVES: Leaves are palmately compound with the narrow leaflets arranged
radially. Fairly dense with silky hairs on both upper and lower surfaces.
RANGE: Frequent throughout the Sonoran Desert in Arizona and Mexico at
roadsides, on rocky slopes and along washes.
FRUIT: Bean capsules split open explosively as each valve twists in
opposite directions - the ten or so bean-seeds are thus ejected a meter or more
away from the parent plant. This is fun for students to observe and ask
questions about: just set up a couple of flowering spikes in vase with water and
wait several days as pods mature and pop open.
UNARMED. No thorns.