Pachycereus grandis is a tree-shaped cactus that can grow 5 to 25 meters tall and is densely branched.

The receptacle tube is 5 to 6 centimeters long and has triangular to lanceolate bracts with an acute to acuminate apex, fleshy texture, and yellowish bristles.

The green tepals form a floral envelope where the calyx and corolla are indistinguishable, featuring consistent shapes and colors in two cycles.

Internal tepals are linear or lanceolate, measuring 3 to 4 centimeters long and can be white, green, or yellow.

[2][3] Pachycereus grandis is commonly found in the Mexican states of México, Michoacán, Morelos, Oaxaca, and Puebla, typically at altitudes between 900 and 1,500 meters.