Euphorbia caput-medusae all about the stem-tip

This Euphorbia caput-medusae stem-tip has leaves right in the centre, each growing from a tubercle tip.

Brownish three-sided pyramid tips, the tiny bud beginnings, grow from the gaps where three tubercles meet. They soon flesh out to take globular shape briefly before their outer segments part, revealing the complex cyathia structure.

The narrow, whitish lobe ends pointing outwards form a spreading fringe around the flower centre. There are five flat olive-green glands, each with three of these lobe appendages, the crooked white fingers of the fringe.

The long, almost cylindrical columns with white tips seen in the background of the stem-tip in the photo are thought to be the remains of spent flowers (Frandsen, 2017; Smith, et al, 2017; Manning and Goldblatt, 1996; iNaturalist).