Euphorbia knuthii

Branching stems with a light, lime green stripe down the columns. Branches grow from a large subterranean caudex. As specimens mature, they can be elevated to the soil surface. Prune top growth when dormant to grow new, bright green stems in the spring.

Euphorbia knuthii is one of those plants which earns its reputation of being an easy plant (it is practically indestructible), with seasonally rapid growth, and for producing remarkable, tuberous roots, which in many plants in cultivation are raised above the soil line so that these can be seen and more readily appreciated. Its thin stems are square in cross section, with two-toned variegation; the tubercles and “ribs” being a darker color, with other portions a lighter green. Plants grown under very bright light may tend to produce additional reddish pigments, and these plants may have a more grey to reddish green coloration to its stems. The stems branch from the tuberous base of the plant, and initially grow upright, but in time, as the stems become increasingly long, and too heavy to support their own weight, these eventually become more scrambling. Short spines are produced in pairs. The spines and spine shields are initially a coppery brown, but will eventually age to a more grayish coloration.