The Beautiful Procession of Palo Verde Flowers

Posted May 10, 2023

by John Scheuring

Across the Sonoran Desert regions of Arizona there is a prolonged Palo Verde bloom each year starting in late March, spanning the entire month of April and extending well into May. Blue Palo Verde (Parkinsonia florida) leads off the flowering and overlaps with the onset of Foothill Palo Verde (Parkinsonia microphylla) in mid to late April. The transition is so subtle that many people are not aware of the two distinct Palo Verde species.

Blue Palo Verde has evolved in desert ephemeral washes where it thrives alongside other species that require more soil moisture than is available on dry desert slopes (bajadas).  Blue Palo Verde flowers are rich deep yellow. Each flower is composed of several petals that are all deep yellow.

Foothill Palo Verde has evolved alongside the Saguaro (Carnegiea gigantea). Both of these species are especially well adapted to well drained desert slopes and can tolerate prolonged periods of drought. Well over 95% of the Palo Verdes in Arizona are Foothill Palo Verdes. Foothill Palo Verde flowers appear distinctly lighter yellow than those of Blue Palo Verdes. The “keel” petal of the Foothill Palo Verde is white while all the other petals are light yellow.

Look up anywhere on our desert slopes and you will find the oft forgotten Foothill Palo Verdes side by side with the iconic saguaro cactus.