The species associated with mining adits are threatened by capping.
metal conduit can without difficulty be covered with wood capping or the like.
The final roof covering will be slate with a lead capping across the ridge.
The protoxylem and protophloem are developed a few cells from the inner and outer margins respectively of the desmogen strand, the desmogenic tissue left over giving rise to the segments of endocycle and pericycle capping the bundle.