TEK - A bare bones attempt at a key for Trichocereus species of interest

[Potter]

A. Spines very stout, formidable
b. Spines yellow .................................................. .............T. terscheckii
bb. Spines dark brown............................................. ...........T. coquimbanus
AA. Spines slender, 1 to 7 cm. long
B. Ribs 4 to 9 (or even 14)
C. Spines yellow (at least when young)................................T. bridgesii
D. Plant (often, not always) dark green;
spines few at each areole or wanting
or 3 to 7 but very short............................................. .T. pachanoi
DD. Plant light green (except for T macrogonus);
spines several at each areole
E. Spines needle-shaped, usually
less then 3.0cm long ..............................................T. macrogonus
EE. Spines awl shaped, tapered,
up to 7cm. long
F. Spines swollen at the base;
young growth green ..........................................T. cuzoensis
FF. Spines not swollen at the base;
young growth glaucous .....................................T. peruvianus
BB Ribs 16 or 17 .................................................. .................T. chiloensis

(Pendell, 2005)

This is far from complete, and does not contain T. taquimbalensis, T. tershekii, T. validus, or T. werdermannianus. I do not know that all species in the key contain mescaline. Systematics for cacti taxonomy are complex and detailed. If flowers are availible, that makes ID far easier, but that is beyond the scope of this document.

[D.A.R.E.]

One mistake many people make is not realizing that the ribs for pedro, torch, achuma, and macro must be thick and round not thin and flat.