Euphorbia vermiculata Rafin. (syn.: Chamaesyce vermiculata (Rafin.) House) (N-Am.) – A very rare but locally naturalized alien. Discovered in 2007 in relative abundance at a former timber storage near Arlon. It was apparently introduced between 1986 and 2000 with timber from Pennsylvania and adjacent states (at the same locality the rare aliens Symphyotrichum pilosum and S. lateriflorum are also found). In 2013 an increased number of plants was detected (comm. A. Remacle).
The plants were initially ascribed to E. humifusa. The latter is (at least the usual race in Europe) always glabrous, has paler seeds and smaller leaves.
Hügin G. (1998) Die Gattung Chamaesyce in Europa. Feddes Repert. 109(3-4): 189-223.