Euphorbia keithii stem-tips

The many upper branchlets of Euphorbia keithii spread and curve in, their upper parts close to erect. Irregularly spaced constrictions are present on the stems, forming segments. The dark green stem segments are usually five-angled or five-winged and oblong, but may have from three to six angles and become cone-shaped at the tips, but not as pronounced as those of E. cooperi. The stem sections become up to 25 cm long and 4 cm wide.

The rudimentary leaves are seen only on young stem parts. They are ovate in shape, about 5 mm long and soon to drop off. The paired spines are thick, 5 mm to 8 mm long, occurring on the hard-edged stem ridges or vertically joined spine shields (Coates Palgrave, 2002; JSTOR; iNaturalist).