Few cacti have such persistently brilliant yellow spines, especially magnificent when backlit, as does this columnar beauty discovered in 1951 by famous nurseryman Harry Johnson on his second South American expedition.  The plant eventually grows to tree-size proportions (6 m.) but even solitary stems, 7-9 cm in diameter, are worth cultivating for the colorful spines which are often long and hair-like in seedlings but soon become short, dense and barely differentiated between centrals and radials.  The species is native to Zangal, Dept. Cajamarca, Peru.  HBG 95204, $7.50.