4 



WEEDS. 



Biennial weeds perish in the second year after perfecting 

 the seeds. They are abundant in the production of seeds, as 

 / well as of plants, and are destroyed with greater difficulty 

 than the former division. 



The Perennial plants are such as exist for an indefinite pe- 

 riod of time : some have the property of perfecting the seeds 

 annually, without being thereby destroyed ; while others, less 

 prolific in seeds, have the faculty of reproduction in their 

 vivacious roots ; while others are capable of increase both by 

 seeds and roots. The plants of this description are much 

 more troublesome and difficult of destruction than the two 

 former divisions. 



For a practical description, the weeds of agriculture may be 

 very conveniently divided into those that infest tillage lands, 

 and the kinds that are found in pasture grounds ; and a third 

 may be added — those that grow in hedge-rows and planta- 

 tions, and are occasionally found on cultivated lands. 



Sect. I. — Tillage Land Weeds. 



1. "Common chickweed," or " Stellaria Media" of bo- 

 tanists, is a very common weed on Hght loams that have been 

 abundantly manured. This genus of plants has been called 

 " Stellaria," from the star-like form of the flowers : it formed 

 the " Alsine" of the older botany, and so called because the 

 plant grows best in woods and shady places. Dr. Withering 

 referred it to the " Stellaria," with which genus it agrees in 

 various respects, and especially in the capsules opening with 

 six valves. The British Flora also refers it to the genus 

 " Stellaria," and characterizes it under the species " Media." 



The genus " Stellaria " belongs to the class and order 

 "Decandria trigynia" of Linneus, and to the natural order 

 "Caryophyllese" of Jussieu. 



Generic character, — Calyx : perianth five-leaved ; leaflets 

 ovate-lanceolate, concave, acute, spreading, permanent. 

 Corolla : petals five, two-parted, flat, oblong, shrivelhng. 

 Stamina : filaments ten, filiform, shorter than the corolla — 

 alternately longer and shorter ; anthers roundish. Pistil : 



