SUNFLOWER FAMILY 541 
Flowers purple, blue, pink, or white; stems more or less angled but not winged. 
Pangea numerous, _subplumose, deciduous, the cc puagwraeel the y's as es to 1 * waar flowers per- 
fect; phy pectinately fringed . C. repens. 
ig depres if Leese spree frequently paleaceous, : mm. Aisle or Seba: eed de in head 
Sterile, r 
Phyllaries with a dria’ or short terminal spin 
Heads 2-3 ong; involu ar spines snes and eosinengga —3 cm. long; fl pink to p 
Paseul & nneingt the paleaceous bristles 1-2 mm. lon 2. C. sber: 
Pappus none. pe ka pore 
Heads 1-1.5 cm. nee, oe seen aeres involucral spines short and oe oy a long; 
flowers white or rarely 
Phyllaries not spine- Nanad or, if middle termi a pond division of the appendage is viata ‘ai ieaiat, 
then the spinule shorter Pt ‘ie lateral “Grice 
Leaves pinnately to bipinnately parted or divided; pice pink; plants biennial or perennial. 
5. C. maculosa. 
Leaves entire or with a few salient lobes ~ = flowers blue or purple, rarely white or pink. 
Plan 
s annual; leaf-blades ig 08 ear to narrowly oblanceolate, 1 cm. wide or less; Letina 
well developed, to aps OF 
Plants perennial; leaves pcan or elliptic, few-lobed ra ries to 3 cm. wide; “papeus 
generally poorly developed or none, if present 1 mm. long or les: 
piacere - middle phyllaries broad and rounded, scarious or lacerate, not pectinate, 
vering the base of ip phy llaries; sterile marginal flowers coletee aor none 
- por re sietted by small si A ope 
Appendages of middle plas pestinate fringed; pappus usually p Z 
Involucre as wide endage of _ egg A dagge bea bre completely covering 
the base of the pet Doe the "ie ciniae se se, mostly once to three times the 
width of the undivided body of the phyllary 
Appendages id phyllaries light to dark beolir, the laciniae about as long as the 
undivided body PF the phyllary; sterile marginal watt Pool a. ey 
enla lla 
Appieisdglics of snstlariae blackish, the laciniae two three times o width of 
the body of the phyllary; sterile marginal Pethestts lacking. 
9. C. nigra 
joudece cylindric, longer than wide; appendage of middle poe he ke gall, not en- 
rely covering the base of the jy bee sterile ma ou enlarged; 
oapiiik reduced t Apnaiivts scales 
Flowers yellow, ~ outermost eure stems. win the an pte eal fase phyllaries weaning salina -tipped. 
Heads about 1.5 cm. long; spines Fy ie "olay acts s 0.5-1 cm. long, slender, purplish- wa Kt i nish- 
ti cok Fiat on the ap 11. C. mel 
Heads about 2 cm. long; spines on oo cage phyllaries 1-2 cm. long, stout, yellow, terete. 
12. C. solstitialis. 
1. Centaurea répens L. Russian Knapweed or Turkestan Thistle. Fig. 5939. 
Centaurea repens L. we lLede2. ng 3: 
Centaurea picris Pall. ex Wil ld. Sp. Pi. 3: 2302. 1804. 
Acroptilon picris Boiss. Fl. Orien. 3: er: 1875. 
Plants perennial with widely anrending: deep-seated rootstocks from which the aerial chee 
arise; stems erect, openly branched, leafy, terete, wingless, 2-10 dm. ta ll. Leaves thinly tomen- 
tulose or glabrate, pale green or canescent, scabrous-margined, the basal leaves sacle shlong” 
oblanceolate, to 8 cm. long and 2 .5 cm. wi = acute, deeply and seeularty pinnately lobed or 
divided, the i nt again lobed or only serrate, acute, petiole shorter than the blade, the lower 
cauline leave what ener pinnately ied 6 r divided or saliently serrate, the upper leaves 
narrowly oxigtag: 13 cm. long, 2-7 mm. wide, maceiwed to a sessile base, abruptly acute and 
5938. Carduus pycnocephalus 
AW 
