Part 1, 1914] CARDUACEAE : HELENIEAE 63 



2. Palafoxia leucophylla A. Gray, Proc. Am. Acad. 8: 291. 1S70. 



Palafoxia arenaria Brand. Proc. Calif. Acad. II. 2: 178. 1889. 



A decumbent perennial, more or less woody; stem 3-10 dm. long; branches divaricate, 



hispid and glandular; leaves densely strigose-canesccnt, linear, 1-3 cm. long, 3-6 mm. wide, 



obtuse; involucre narrowly turbinate-campanulate, 10-12 mm. long; bracts linear, densely 



hispid and glandular; corollas about 15, flesh-colored; tube 3 mm. long; throat about 4 mm. 



and lobes 1.5 mm. long; achenes 6-8 mm. long, 1 mm. wide; pappus of 3-5 squamellae, about 



5 mm. long, with strong midrilj. 



Type locality: Carmen Island, Lower California. 

 Distribution: Lower California. 



3. Palafoxia Feayi A. Gray, Proc. Am. Acad. 12: 59. 1876. 



A perennial, suffruticose at the base; stem terete, minutely scabrous, 3-7 dm. high; 



leaves short-petioled; blades oblong or elliptic, rounded at both ends, or the uppermost acute 



at the apex, 3-ribbed at the base, scabrous-hispidulous; heads corymbose; involucre turbinate, 



about 1 cm. high and broad; bracts spatulate-linear, truncate or rounded at the apex, purplish; 



corollas 15-20; tube 2 mm. long; throat cylindric, 4 mm. long; lobes oblong, 1.5 mm. long; 



pappus-squamellae 8, oblong, 1-1.5 mm. long. 



Type locality: South Florida. 

 Distribution: Florida. 



Subtribe 8. CHAENACTIDANAE. Heads discoid, or if radiate ligules 

 inconspicuous, not longer than the disk. Involucre turbinate, campanulate, 

 or nearly cylindric; bracts narrow, linear or linear-lanceolate, usually ap- 

 pressed. Disk-flowers yellow to white or flesh-colored, the short tube much 

 shorter than the throat, which is nearly cylindric or in the marginal 

 flowers somewhat funnelform or trumpet-shaped. Achenes scarcely angled 

 (4-angled in ChamaechaenacHs) , terete or oval in cross-section, striate, linear 

 or clavate. 



Heads radiate, but rays inconspicuous, not longer than the disk; pappus- 

 squamellae opaque. elonRute; leaves entire. 44. Rigiop.\ppus. 

 Heads discoid, but the marginal tlowers sometimes enlarged and irregular; 

 pappus of hyaline squamellae. 

 Achenes angled; pappus-squamellae with strong midribs; scapose 



plants with entire broad leaves. 45. Cha.maechaEnactis. 



Achenes scarcely angled ; pappus-squamellae not conspicuously ribbed ; 

 plants usually caulescent, if not, leaves at least lobed. 

 Bracts many; heads peduncled; sciuamellae of the pappus distinct 

 or rarely wanting; style-tips subulate; leaves usually pinnately 

 dissected or pinnately lobed. 46. Chaenactis. 



Bracts 4; heads sessile; squamellae of the pappus united at their 

 base and falling off together; style-tips obtuse leaves narrowly 

 linear. 47. Orochaenactis. 



44. RIGIOPAPPUS A. Gray, Proc. Am. Acad. 6: 548. 1865. 



Slender puberulent annual herbs. Leaves alternate, linear, entire. Heads solitary at 

 the ends of the stem and several smaller ones on elongate peduncles from the upper axils. 

 Involucre turbinate ; bracts subequal, in two series, linear-subulate, concave, partly enclosing 

 the ray-flowers. Receptacle plain, naked. Ray-flowers 5-8, pistillate, fertile, with short lig- 

 ules scarcely exceeding the disk. Disk-flowers hermaphrodite, fertile; corolla-tube slightly 

 shorter than the tubular throat; teeth 3-4, short. Style-branches of the hermaphrodite 

 flowers partly stigmatose, short, glabrous, flattened with subulate hirtellous tips. Achenes 

 slender, linear, compressed, hispid, transversely rugose. Pappus simple, of 4 or 5 ridged 

 subulate aristiform squamellae. 



Type species, Rigiopappus leptocladus A. Gray. 



Squamellae slightly longer than the disk -corollas. 1- R- leptocladus. 



Squamellae about twice as long as the disk -corollas. 2. R. longtanslaliis. 



