Synthetic fuel Ruhr Area. In 1937, the four central Germany lignite coal plants at Böhlen, Leuna, Magdeburg/Rothensee, and Zeitz, along with the Ruhr Area bituminous coal plant at Scholven/Buer, had produced of fuel. Four new hydrogenation plants () were subsequently erected at Bottrop-Welheim (which used "Bituminous coal tar pitch"), Gelsenkirchen (Nordstern), Pölitz, and, at 200,000 tons/yr Wesseling. Nordstern and Pölitz/Stettin used bituminous coal, as did the new Blechhammer plants. Heydebreck synthesized food oil, which was tested on concentration camp prisoners. The Geilenberg Special Staff was using 350,000 mostly foreign forced laborers to reconstruct the bombed synthetic oil plants, and, in an emergency
Evolutionary history of plants billion years ago, and that communities of complex, multicellular photosynthesizing organisms existed on land in the late Precambrian, around . Evidence of the emergence of embryophyte land plants first occurs in the mid-Ordovician (~), and by the middle of the Devonian (~), many of the features recognised in land plants today were present, including roots and leaves. Late Devonian (~) free-sporing plants such as "Archaeopteris" had secondary vascular tissue that produced wood and had formed forests of tall trees. Also by late Devonian, "Elkinsia", an early seed fern, had evolved seeds. Evolutionary innovation continued into the Carboniferous and still continues