FAUNA AND FLORA OF MANGROVE SWAMPS
137
FIG. 36. Diagrams to show the rooting system of species of Rhizophom. There is no
tap root, and the prop roots end in a knob-like mass from which anchoring roots
radiate. The uppermost ones bear most of the nutritive roots (cf. Fig. 35).
uppermost layers of the soil. In Bruguiera and Ceriops a system of
air-filled cable roots send knees up above the surface and these possess
lenticels (Fig. 3 7 ) : nutritive roots are also given off in the subsurface
layers.
The rooting systems of Xonneratia spp., Avicennia spp. and Xylocarpus spp. have no tap roots a t any time. These trees develop very
extensive systems of cable roots which lie some 20-50 em below the
surface (Fig. 38). Many specimens of Xonneratia and of Avicennia
137
FIG. 36. Diagrams to show the rooting system of species of Rhizophom. There is no
tap root, and the prop roots end in a knob-like mass from which anchoring roots
radiate. The uppermost ones bear most of the nutritive roots (cf. Fig. 35).
uppermost layers of the soil. In Bruguiera and Ceriops a system of
air-filled cable roots send knees up above the surface and these possess
lenticels (Fig. 3 7 ) : nutritive roots are also given off in the subsurface
layers.
The rooting systems of Xonneratia spp., Avicennia spp. and Xylocarpus spp. have no tap roots a t any time. These trees develop very
extensive systems of cable roots which lie some 20-50 em below the
surface (Fig. 38). Many specimens of Xonneratia and of Avicennia