58 



WEEDS. 



oi'der " Syngenesia polygamia frustranea " of Linneus, and 

 the natural order " Cinarocephalse " of Jussieu. 



Generic character. — Calyx common, imbricated, round- 

 ish ; scales variously terminated. Corolla compound, flos- 

 cular ; florets diflering in form ; those of the disk hermaph- 

 rodite, numerous ; those of the ray fewer, loose, larger, fmmel- 

 shaped, constantly abortive ; tube of the hermaphrodite 

 florets filiform ; border bellying, oblong, erect, terminated by 

 five linear erect segments; tube of the abortive florets slender, 

 gradually enlarging, recurved ; border oblong, oblique, un- 

 equally divided. Stamina of the hermaphrodite florets : fila- 

 ments five, capillary very short ; anthers united into a hollow 

 cylinder the length of the petal ; of the abortive florets none. 

 Pistil of the former : germ small ; style filiform ; the length 

 of the stamens; stigma very obtuse, projecting in a point; 

 in many species bifid ; of the latter germ very small ; style 

 scarcely any ; stigmas none. Seeds of the fertile florets soli- 

 tary ; down in most species feathered or capillary ; receptacle 

 bristly. 



Essential character. — Receptacle bristly. Florets of the 

 ray funnel-shaped, longer, abortive. 



The common pasture w^eed is the species "Centaurea nigra'* 

 of botany, which has the calyxes cihate, with the little scale 

 ovate ; cilias, capillary, erect ; leaves lyrate, angular ; flowers 

 floscular. Stem from two to three feet in height, angular, 

 scored, slightly downy, often tinged with purple. It has many 

 provincial names, as knap-w"eed, knop-w^eed, knob-weed, 

 horse-knops, all from " knob or nob," a head ; also " hard- 

 heads, hard-irons ;" and in Scotland it is called " horse-knot." 

 It is a very harsh, stubborn plant, seldom touched by cattle, 

 either green or in hay, and is with difiiculty extirpated. It 

 is perennial, and matures an abundance of seeds. 



The seeding of the flowers must be prevented by cutting 

 the plants when half grown by the scythe or hand sickle, and 

 the roots must be raised and destroyed by spades and forks. 



22. The Wood or meadow anemone," the Anemone 

 nemorosa" of botany, is a plant very common in meadows, - 

 though disregarded by farmers. The plant belongs to the 



