  Let $(\Sigma,p)$ be a pointed Riemann surface of genus $g\geq 1$. For any
integer $k\geq 1$, we parametrize the space of meromorphic quadratic
differentials on $\Sigma$ with a pole of order $(k+2)$ at $p$, having a
connected critical graph and an induced metric composed of $k$ Euclidean
half-planes. The parameters form a finite-dimensional space $\mathcal{L} \cong
\mathbb{R}^{k} \times S^1$ that describe a model singular-flat metric around
the puncture with respect to a choice of coordinate chart. This generalizes an
important theorem of Strebel, and associates, to each point in a decorated
Teichm\"{u}ller space $\mathcal{T}_{g,1} \times \mathcal{L}$, a unique metric
spine of the surface that is a ribbon-graph with $k$ infinite-length edges to
$p$. The proofs study and relate the singular-flat geometry on the surface and
the infinite-energy harmonic map from $\Sigma\setminus p$ to a $k$-pronged
graph, whose Hopf differential is that quadratic differential.
