\definecolor{mygreen}{HTML}{129d1c}
\begin{tikzpicture}[>=latex, node distance=1cm, on grid, auto]

\node (S1) [draw, regular polygon, regular polygon sides=3, minimum
size=1cm, shape border rotate=180, color=mygreen] {}; %{;};
\path (S1.west)+(-0.5,-1) node (A2) [circle, minimum size=0.5mm] {};
\path (S1.east)+(0.5,-1) node (S2) [draw, rectangle, minimum size=0.5mm, color=mygreen] {};

\path[-,color=mygreen] (A2) edge (S1);
\path[-,color=mygreen] (S1) edge (S2);

\path (S1.west)+(-1,-0.25) node (arrow) [minimum size=0.5cm] {$\longrightarrow$};
\path (arrow.west)+(-0.5,0) node (seq) {;};

\end{tikzpicture}
