First appeared on p. 144 in:

 Britton & Rose's The Cactaceae

18. Trichocereus shaferi sp. nov.

Description:
   Cespitose, cylindric, 3 to 5 dm. high, 10 to 12.5 cm. in diameter, light green; ribs about 14, 10 to 15 mm. high; areoles approximate, 5 to 7 mm. apart, white-felted when young; spines about 10, acicular, 12 mm. long or less, light yellow; flowers from the top of plant, 15 to 18 cm. long; tube slender; outer perianth-segments linear; inner segments probably white; scales of the ovary and flower-tube bearing long brown hairs.
   Collected by J. A. Shafer in wooded ravine, altitude 1,800 meters, near San Lorenzo, Salta, Argentina, January 11, 1917 (No. 44).