Trichocereus Terscheckii  

Body: At first columnar with an intense green, woody trunk up to 17.75"
(45cm.) diameter, to 40' (12m.) tall. When older becomes branched with
parallel, ascending branches to 8" (20cm.) diameter. Often confused
with T. pasacana but is more branched, fewer ribs, different spines
and larger flowers.

Ribs: 8-14, prominent, obtuse, to 1.6" (4cm.) high.
Areoles/Spines: Areoles felted, to .6" (1.5cm.) diameter, to 1.2"
(3cm.) apart.

Spines: yellow, 8-15, tapering to a fine point, to 3.1" (8cm.) long.
Flowers/Fruit: Large flowers to 8" (20cm.) long, 4.75" (12cm.) broad.
Distribution: Northern Argentina.
Subspecies: v. montanus: Branches lighter green, obliquely ascending.

Tall arborescent Native to Catamarca, Argentina.
Contains: mescaline, trichocereine.

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http://www.desert-tropicals.com/Plants/Cac...erscheckii.html

Recommended Temperature Zone: sunset: -
USDA: 8b-11

Frost Protection: Hardy to 18° F (-8° C)
Heat Tolerance: Light shade in Phoenix
Sun Exposure: Full sun
Origin: Northern Argentina
Growth Habits: Columnar cactus branching above ground, reaches
over 25 feet tall (7.5 m), branches are around 10
inches in diameter (25 cm)

Watering Needs: Little water, needs good drainage
Propagation: Seeds

In age becoming much branched, 10 to 12 meters high; trunk woody, up to 4·5 cm. in diameter; branches 1 to 2 dm. in diameter; ribs 8 to 14, prominent, 2 to 4 cm. high, obtuse; areoles large, 1 to 1.5 cm. in diameter, felted, 2 to 3 cm· apart; spines 8 to 15, subulate, yellow, up to 8 cm. long; flowers very large, 15 to 20 cm. long, 12.5 cm. broad; inner perianth-segments oblong, 7 cm. long, acute, white ;scales on the ovary and Flower-tube ovate, mucronate-tipped, their axils filled with long brown wool.

This is a very large cactus, called in Argentina cardon grande. It has frequently been confused with another species, T, pasacana, of the same region, but it is more branched, with fewer ribs, different spines, and large flowers.