(Named in honor of C. G. Pringle, botanist and collector of southwestern plants) How to identify and how it grows The stems of this species grow singly or occasionally in clumps of a few. They are three to nine feet tall, something over a foot in diameter. Their ribs are quite prominent. The spines form in a marginal fringe of white bristlelike inch-long hairs that are bent and twisted, four to eight radials and four centrals, two inches long or less, cross-ridged and light red and yellow at their bases. The flowers encircle the tips of the stems in an orange-yellow cluster of twenty petals and sepals, each one an inch or so long and broad, and formed like a bell. The fruit is elliptical, orange or red, and is filled with a colorless limelike juice from which delicious lemonade is made; hence the common name, Lime Cactus. The plants thrive in the loamy soil of foothills and mountains in Central Mexico. How to grow Set out in spring in loamy soil or sandy loam in a sunny exposure with moderate irrigation. The seed may be sown in June in sandy loam, in flats in part shade and with enough irrigation to keep the soil moist. The plants thrive either out of doors or within and are not injured at twenty-five degrees below freezing; but with zero weather they require some protection. 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