Sentence:  Common <WSD>Pimpernel</WSD> has diverse weak square stalks lying on the ground, beset all along with two small and almost round leaves at every joint [...]. 
Meaning of the word marked with <WSD> tags:  Any of various plants of the genus (Anagallis), having small red, white or purple flowers, especially the scarlet pimpernel, (Anagallis arvensis). (from 15th c.)