Fundamentals of Botany pp. 50-51 (1916)
By Charles Stuart Gager

The tip of the root is covered by a root-cap (Fig. 37), composed of cells that serve to protect the delicate tip as it grows through the soil. In some cases, as in the water-hyacinth (Figs. 38 and 39), the root-cap is so well developed that it may be easily seen with the naked eye, and quite readily removed and replaced. root-hairs are never found on the region covered by the root-cap.

 
Fig 37.óJack-in-the-pulpit (Arisaema triphyllum). Longitudinal section through a root. rt, root-tip; rc, root-cap. (After F. L. Pickett.)   Fig. 38. óRoots of the water-hyacinth (Eichornia crassipes Solms), showing removable root-caps; b, root-cap removed from c.

 

Fig. 39. óWater-hyacinth (Eichornia crassipes). Photomicrograph of a longitudinal section of a root, showing the mode of origin of lateral roots (i.e. endogenous). a, b, c, lateral roots; r. t, root-cap.

Root structures, exudates, mineral uptake