COMPOSITACEAE (COMPOSITE FAMILY) 237 



MM. Akenes somewhat flat. 



P. Akenes beakless, truncate; heads so-flowered or more. SONCHUS (p. 237) 

 PP. Akenes beaked or attenuate; heads 6-3O-flowered. LACTUCA (p. 238) 



AA. Flowers white or pink or blue or purple; stems leafy or bracted. 

 Q. Pappus a crown of short blunt scales; heads sessile or nearly so, in spikes or 

 racemes. W. Root a substitute for coffee. (From chikouryeh, its Egyptian 

 name.) Cichorium intybus (CHICORY) 



QQ. Pappus of simple bristles though often scabrous. 



R. Flowers white; leaves and lower part of stem with long white stiff spreading 



hairs; leaves lanceolate to oblong, entire. HTERACIUM (p. 238) 



RR. Flowers not white; plant without long white stiff spreading hairs; leaves 



usually not as described above. 



S. Leaves entire, lanceolate or narrower, not sagittate at base; flowers rose- 

 colored or pink; akene terete, neither flat nor angled. E. (Gk. lygos = a twig, 

 desma = a bundle ; referring to the tufted rushlike stems.) Lygodesmia 



SS. Leaves either not entire or else sagittate at base; flowers pink or blue or 



purplish; akene terete or 4-s-angled or somewhat flat. 



T. Akene terete or 4-s-angled, not flat; pappus tawny; leaves deltoid-hastate 

 but becoming narrower up the stem; plant 3-6 dm. high. W. C. (The 

 Latinized Indian name for the Rattlesnake-root.) 



Nabalus hastatus (RATTLESNAKE ROOT) 



TT. Akene somewhat flat; pappus white; leaves several times as long as wide; 

 plant usually taller. LACTUCA (p. 238) 



QQQ. Pappus of plumose bristles. 



U. Heads solitary and terminating a leafy stem, 5-10 cm. wide; leaves all entire; 

 akene with long slender beak; flowers purple. W. E. Cultivated as a vegetable 

 for its root. (Gk. tragos = a goat, pogon = a beard; referring to the con- 

 spicuous tawny pappus.) Tragopogon porrifolia (OYSTER PLANT) 

 UU. Heads in panicles or corymbs, 2.5 cm. or less wide; mostly with at least the 



basal leaves not entire; flowers pink or white. 



V. Akene tapering into a slender beak as long as the body; involucre 18-25 mm. 



high, is-30-flowered. E. ^(Probably in honor of C. S. Rafinesque, an American 



botanist.) Rafinesquia calif ornica 



W. Akene truncate, beakless; involucre 6-15 mm. high, 3-6-flowered. E. (Gk. 



ptilon = a feather ; referring to the plumose pappus.) Ptiloria 



SONCHUS (Sow THISTLE) 



Stem leafy. Leaves mostly auriculate-clasping, entire to pinnatifid, 

 prickly-margined. Heads in corymbs or panicles; receptacle naked. 

 Corolla yellow. Pappus of bristles ; bristles many, white, capillary, simple. 

 (Gk. sonchos = hollow ; referring to the stem.) 



A. Involucre glandular-pubescent, 25 mm. high; flowers bright yellow; perennial; 

 leaves with acute basal angles; akenes transversely wrinkled. W. E. 



S. arvensis (FIELD sow THISTLE^ 



AA. Involucre glabrous, 12-16 mm. high; flowers pale yellow; annual. 

 B. Leaves with acute basal angles; akenes transversely wrinkled. W. 



S. oleraceus (COMMON sow THISTLE) 



BB. Leaves with rounded basal angles; akenes not transversely wrinkled. W. E. 



S. asper (PRICKLY sow THISTLE) 



