Tiarella flower spike

In Tiarella breeding and variety testing, flower spike height is measured at the full bloom stage as the distance from the base of the leaf rosette to the top of the inflorescence. A characteristic feature of many cultivars is the ability of the flower spikes to 'hover' above the foliage, often rising 1–2 times higher than the leaves.

Flower spike height in most cultivars varies from 15 to 45 cm depending on the species. When evaluating ornamental quality, preference is given to sturdy stalks that ensure an upright position of the inflorescences, which is critical for creating the characteristic visual effect of a cloud above the leaf canopy.