melancholy thistle: perennial stoloniferous thistle of northern Europe with lanceolate basal leaves and usually solitary heads of reddish-purple flowers
plant: (botany) a living organism lacking the power of locomotion
williams syndrome: a rare congenital disorder associated with deletion of genetic material in chromosome 7; characterized by mental deficiency and some growth deficiency and elfin faces but an overly social personality and a remarkable gift for vocabulary