Limestone high quality quarried limestone, called Indiana limestone. Many famous buildings in London are built from Portland limestone. Limestone was also a very popular building block in the Middle Ages in the areas where it occurred, since it is hard, durable, and commonly occurs in easily accessible surface exposures. Many medieval churches and castles in Europe are made of limestone. Beer stone was a popular kind of limestone for medieval buildings in southern England. Limestone and (to a lesser extent) marble are reactive to acid solutions, making acid rain a significant problem to the preservation of artifacts made from this stone.
Gymnadenia conopsea Gymnadenia conopsea Gymnadenia conopsea, commonly known as the fragrant orchid or marsh fragrant orchid, is a herbaceous plant belonging to the family Orchidaceae native to northern Europe. The name of the genus "Gymnadenia" is formed from Greek words (', "nude") and (', "gland") and refers to the characteristics of the organs for secreting nectar. The specific Latin name "conopsea" derives from the Greek ' ('), literally meaning "mosquito-like", probably because of the similarity of the long spur of the flower with the mouthparts of a mosquito. The scientific binomial name of this plant was initially "Orchis conopsea", proposed by the