Stem surfaces of Euphorbia filiflora are covered in spirally arranged tubercles. The variously shaped tubercles have about four or five facets meeting adjacent tubercles fairly neatly in narrow, sunken seams.
When the young tubercle emerges at the stem-tip, it bears a leaf once in its first winter, the growing season. Slightly pointed in its centre, each fleshy tubercle is scarred where its leaf had dropped off.
As the short-lived leaves drop off, new leafy tubercles grow from the stem-tip. The old ones retain their leaf scar badges upon relegation to positions increasing further from the tip of the lengthening stem. A bit like war medals for old soldiers, conveying recognition and respect (Frandsen, 2017; Williamson, 2010; iNaturalist).