Giant Visnaga (Echinocactus Visnaga)
(“Visnaga” is the Mexican name of the plant)
How to identify and how it grows
These are giant barrel plants, greenish monsters growing to nine feet in height, a single trunk often four feet through, cylindrical, the top broadly rounded with the center somewhat sunken. Along this stem run thirty to forty inch-high glossy green ribs with wavy crests, and a dense mass of long tan woolly areolas. There are four straight, stout, sharp one- or two-inch thorns with smooth surfaces, creamy yellow or translucent with brownish tips. The bright yellow flowers are quite narrow, a little less than three inches in length, and covered with a dense layer of cream-yellow hairs. These great plants grow singly on the highlands of San Luis Potosí, Central Mexico, and often attain an age of a thousand years and a weight of over five thousand pounds.
How to grow
This rare cactus grows very slowly. It thrives in sandy or gravelly clay loam with sunny exposures, and with occasional irrigation to moisten the soil during dry periods and during the growing season. The plants will grow out of doors or indoors and are not injured by a temperature twenty-five degrees below freezing; from zero weather they should be given protection.
Whipple’s Visnagita (Echinocactus Whipplei—Sclerocactus Whipplei)
(Named in honor of Lieutenant A. W. Whipple, in charge of the Whipple Expedition in 1853-1854, when this plant was discovered)
How to identify and how it grows
This little cactus grows only three to six inches tall, and about the same in diameter, singly or occasionally in clumps. It is generally to be seen growing in the protection of shrubs at about five thousand feet. The stem is lined with thirteen to fifteen prominent spiraled ribs, and seven to eleven white radial spines. There are also four black and white central thorns which turn red and finally ash-colored, and the lowest of these spines is sharply hooked. The flowers cluster at the top of the plant, bell-shaped blossoms purplish or rose-tinged, with a reddish style hairy its full length. The reddish fruit is oblong and has colorless scales, each of which bears a tuft of hairs in the axil.