A type of tree that is symbiotically cultivated by the Narayani.
Naturally, the "lattice" is a large, algae-like plant. It grows mostly around the underwater geothermal vents that occur in the oceans of Narayan. Its roots are thick and long, and when the plant is well-nourished with the copious mineral sediment produced by the heated water, they can be nearly impenetrable; from the central stalk or stem they can reach nearly a mile of length with numerous tendrils and branches forming a weblike latticework.
Narayani civilization is entirely founded upon its ability to capture puffer spores and use them to support growing lattice; they Weave the roots into netlike enclosures around the green, inflated spore sacs so that the roots entwine and grow upward and create stable lattice-based structures.
The Lattice Tree ends up a billowing organic structure with spore sacs entwined by a latticework of thick roots. This is the foundation on which Narayani cities exist.
These structures require constant but delicately balanced maintainance: trimmed regularly so that the root-net won't smother the spores; and carefully so that the spores won't break free.