The dogwood, a popular ornamental tree of white and pink blooms, has also been called the "dogger tree," "hounder tree," and "dogge berie tree." Does it have any connection to our canine friends? One theory is that the tree's bark was used to help rid dogs of fleas. Another theory traces the name to the Old English word "dagge," a spit or skewer, because the hard, smooth wood of the European dogwood was good for spitting meat.
In Medieval Latin, lavender was livendula, from livere, "to make bluish." The plant was commonly used to scent linen and make soaps and perfumes back when people seldom bathed. Laundresses used branches from the aromatic plant to beat washed clothes and bedding to scent them. Hence, the expression "to lay out in lavender," meaning to knock someone down or severely chastise.
SOURCES: 'Why You Say It' by Webb Garrison; 'A Second Browser's Dictionary' by John Ciardi; 'The Encyclopedia of Word and Phrase Origins' by Robert Hendrickson; '100 Flowers and How They Get Their Names' by Diana Wells; 'Dictionary of Word Origins' by Jordan Almond.