\documentclass[border=5mm]{standalone}
\usepackage{luamplib}
\begin{document}
\mplibtextextlabel{enable}
\begin{mplibcode}
input colorbrewer-rgb
vardef bush(expr start, aim, level, limit) = 
    save s, target; 
    numeric s; s = level / limit;
    for a = -32, -8, 8, 16:
        pair target; 
        target = aim scaled ((32 + 16 normaldeviate) * s) rotated a shifted start;
        draw start -- target 
            withpen pencircle scaled s
            withcolor BrBG[limit][limit-level];
        if level > 1:
            bush(target, aim rotated a, level - 1, limit);
        fi
    endfor
enddef;
beginfig(1);
bush(origin, dir 80, 6, 8);
endfig;
\end{mplibcode}
\end{document}