Coulter's Lupine
Lupinus sparsiflorus
Photographed in Maricopa County, Arizona. March 2008. Also on the inflorescence there is a Blister Beetle, g. Lytta.
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.
LEAVES: Leaves are palmately compound with the narrow leaflets arranged
radially. Fairly dense with silky hairs.
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.
UNARMED. Without thorns.