Crosswort is a name commonly applied to several plants, including: ...
• (n.) A name given to several inconspicuous plants having leaves in whorls of four, as species of Crucianella, Valantia, etc.
(from the article `Rubiaceae`) ...Houstonia (bluets), and Cephalanthus (buttonbush). Common madder (Rubia tinctorum) was formerly cultivated for the red dye obtained from its roots ...
Cross'wort` noun (Botany) A name given to several inconspicuous plants having leaves in whorls of four, as species of Crucianella , Valantia , etc.