root cap
Noun
Meaning
thimble-shaped mass of cells covering and protecting the growing tip of a root
Source: WordNetHypernyms
Examples
The meristem cells more or less continuously divide, producing more meristem, root cap cells (these are sacrificed to protect the meristem), and undifferentiated root cells.
Katz and Weaver, p. 279 The word brassica derives from bresic, a Celtic word for cabbage. citation Many European and Asiatic names for cabbage are derived from the Celto-Slavic root cap or kap, meaning "head".
The epidermis of roots originates from the layer of cells immediately beneath the root cap.