position in order that the bottom portions of the respective planks 10 a can conform to a concave area of a lake or water shore edge plants and the like are then introduced into the connected planks latticework and as they grow the root structure firmly anchors the erosion control planks in place the placing of the erosion control plank 10 a in such a concave position shows their ability to form a concave curve to more completely cover a concave eroded zone formed proximal to the intersection of a concave curved perimeter of a lake stream canal ocean or pond fig8 b is a plan view of two connected erosion control planks of the first embodiment of the invention the first erosion control plank 10 c and the second erosion control plank 10 d erosion control plank 10 c is connected to erosion control plank 10 d by the bottom rightmost male connection member 45 a of plank 10 c matingly engaging the bottom leftmost female connection member 45 e u2032 of plank 10 d the top of erosion control plank 10 c is pulled to the right and the top of erosion control plank 10 d is pulled to the left pivoting about the intersection of the connection elements 45 a and 45 e u2032 this causes the plurality of vertical walls of the lattice of plank 10 c to no longer be in parallel relation with the plurality of vertical walls of plank 10 d further the plurality of horizontal walls of plank 10 c begin to overlap the plurality of horizontal walls of plank 10 d on their right and left side respectively the overlap increasing in magnitude from the bottom of both planks 10 c and 10 d to the top.