GENUS 108. 



THISTLE FAMILY. 



557 



i. Centaurea Cyanus L. Blue-bottle. 



Corn Blue-bottle. Corn-flower. 



Fig. 4656. 



Cen'.aurea Cyanus L. Sp. PI. 911. 1753. 



Annual, woolly, at least when young; stem 

 leafy, slender, branched, i-2i high, the branches 

 ascending. Leaves linear or linear-lanceolate, 

 mucronate, 3'-6' long, the basal and lower ones 

 mostly remotely dentate, the upper, or sometimes 

 all of them, entire; heads I'-lj' broad, on long 

 naked peduncles ; involucre campanulate, its bracts 

 greenish-yellow, or the inner with darker tips 

 and margins, appressed, fimbriate with scarious 

 teeth; flowers blue, purplish, pink or white, the 

 marginal ones neutral with large radiant corolla- 

 limbs ; achenes slightly compressed, or 4-angled ; 

 pappus bristles unequal, nearly as long as the 

 achene. 



In waste places, escaped from gardens, and in bal- 

 last, Quebec to Ontario, western New York, Nebraska 

 and Virginia. Witches'-bells or -thimbles, corn- 

 centaury, corn-bottle or -binks. Brushes. Hurt-sickle. 

 Blue-bonnets. Blaver. Blue poppy. Bachelor's-but- 

 tons. Blue caps. Barbeau. French pink. July-Sept. 



2. Centaurea Jacea L. Brown or Rayed 



Knapweed. Fig. 4657. 



Centaurea Jacea L. Sp. PI. 914. 1753. 



Perennial, 2 high or less. Leaves entire or 

 denticulate, rarely lobed ; heads i'-ii' broad; in- 

 volucre globular to ovoid, its bracts closely im- 

 bricated, brown or with brown backs, the outer 

 ones pale brown with fimbriate appendages, the 

 middle ones lacerate, the inner entire or nearly 

 so, dark brown ; marginal flowers neutral with 

 enlarged radiant corolla-limbs ; achenes obscurely 

 4-sided ; pappus none, or a minute crown. 



In waste places, northern New York, Vermont and 

 Massachusetts, and in ballast about eastern seaports. 

 Also in British Columbia. Fugitive from Europe. 

 June-Sept. 



3. Centaurea nigra L. Black Knapweed. 

 Horse-knops. Hardheads. Centaury. 



Fig. 4658. 



Cen aurea nigra L. Sp. PI. 911. 1753. 



Perennial, scabrous or pubescent ; stem stiff, 

 branched, i-2 high. Lower and basal leaves 

 spatulate or oblong, acutish, entire, denticulate, 

 dentate or lobed, not pinnatifid, 3'-6' long, nar- 

 rowed into long petioles ; upper leaves oblong or 

 lanceolate, sessile, or partly clasping, entire or 

 nearly so; heads rarely i' broad, bracted by the 

 small, uppermost leaves ; involucre globose, its 

 bracts lanceolate or ovate-lanceolate, closely im- 

 bricated, tipped with brown fimbriate appendages, 

 or the uppermost merely lacerate ; flowers rose- 

 purple, all perfect, the marginal ones usually not 

 at all enlarged, or sometimes radiant ; achenes 

 slightly 4-sided ; pappus none, or a ring of minute 

 scales. 



In waste places and fields, Newfoundland to On- 

 tario, New Jersey and Pennsylvania. Naturalized 

 from Europe. Among many other English names are 

 iron-head or -weed, club-weed, matfelon, hurt-sickle, 

 tassel, horse-knobs ; crop-, knob-, bole- or button- 

 weed ; loggerheads, lady's-cushion, blue-tops, hard- 

 weed, bullweed, sweeps, bachelor's-buttons. July- 

 Sept. 



