55 S 



i OMPOS] i \i 



Vol. III. 



4. Centaurea Scabiosa L. Scabious Knapweed. 

 Greater Centaury. Fig. 4659. 



C. Scabiosa I -. Sp. PI. 913. 1753. 



Slightly pubescent or villous, perennial; stem simple 

 or branched, about 2 high. Leaves all pinnatifid, the 

 lower and basal ones petioled, often 6' long, the upper 

 sessile and much smaller; heads about 2' broad, on 

 bracted peduncles I '-4' long; involucre ovoid, its bracts 

 all pectinate to or below the middle, and blackish-mar- 

 gined, the outer ovate, the inner oblong ; corolla purple, 

 the outer ones enlarged and neutral; pappus of stiff 

 bristles, about as long as the achene. 



Waste grounds and fields, Quebec and Ontario to Ohio. 

 Naturalized from Europe. July-Sept. 



5. Centaurea vochinensis Bernh. Tyrol Knap- 

 weed. Fig. 4660. 



C. vochinensis Bernh.; Reichenb. Icon. Fl. Germ. 15: 15. 

 1S53. 



Perennial, roughish, branched, 2 high or less. Leaves 

 firm in texture, the basal and lower ones dentate or 

 lyrate, 3-5' long, the upper lanceolate to oblong-lanceo- 

 late, few-toothed or entire; heads about ii' broad; in- 

 volucre ovoid-cylindric, about 8" high, its faintly nerved 

 bracts pectinate at the brownish tip, the lower short, 

 ovate, the upper elongated ; flowers rose-purple, the 

 margined ones radiant. 



Waste grounds, Ontario to Massachusetts and southern 

 New York. Naturalized fror.i Europe. Aug. -Oct. 



6. Centaurea maculosa Lam. Spotted Knap- 

 weed. Fig. 4661. 



C. maculosa Lam. Encycl. 1: 669. 1783. 



Annual or biennial, loosely floccose-pubescent or 

 glabrate, usually much branched, 2s high, the stiff 

 branches ascending. Leaves pinnatifid into linear 

 segments, or the upper linear and entire, the lower 

 up to 3' long ; heads peduncled, about 10" broad ; 

 involucre ovoid, its ribbed bracts pectinate only at 

 the black tip, the inner ones longer than the outer 

 and entire or merely erose; corollas white to purple, 

 the marginal ones radiant. 



Waste grounds, Massachusetts to New Jersey and 

 Pennsylvania. July-A'ig. 



