84 PROCEEDINGS OF THE AMERICAN ACADEMY. 



§ 4. Heteropectis, Gray. Low diffuse puberulent plants with setif- 

 erous leaves : rays bright yellow : pappus of corneous subulate divergent 

 retrorsely barbed awns (or reduced in the disk to a mere crown of rigid 

 s<iuamelliE). — PI. Wright, i. 83. Pedis § Pectidium, Gray, Proc. Am. 

 Acad. xix. 48, in part. 



* Leaves thick, serrulate, the teeth and the tip continued into long setae. 



P. multiseta, Benth. Annual, stouter than the related species, 

 3 dm. or less liigh : leaves with slightly revolute margins, lanceolate, 1 to 

 2|^ cm. long, the lower surfaces covered with scattered large glands and 

 smaller punctate dots : peduncles becoming 3 cm. long: involucre A\ mm. 

 high, 20-25-flowered, of 5 obovate-cuneate punctate and ciliate bracts : 

 rays 6 mm. long: awns unequal in length (2 mm. or less), in the ray- 

 flowers 3, in the disk-flowers 1 or 2, or the pappus reduced to a mere 

 crown of more or less connate squamellaj : akenes 3 or 4 mm. long, pu- 

 bescent with long somewhat capitate hairs. — Bot. Sulph. 20. — Loaver 

 California, Cape St. Lucas (Hinds ^6?e Bentham, 1. c. Xantus). 



* * Leaves thniner, setiferous only below the middle. 



P. Coulteri, Harv. & Gray. Annual or perennial (?), slender, very 

 diffuse and branched, 2 dm. or less in height : leaves narrowly linear, 

 usually with revolute margins, 3 cm. or less in length, generally with 2 

 rows of glands on the lower surfaces ; setae restricted to the subpinnatifid 

 basal half of the leaf : peduncles varying in length from 3 or 4 mm. to 

 3J cm. ; involucre cylindraceous, 12-20-flowered, 5 to 7| mm. high, of 5 

 (or by exception 6) linear-oblong often glandular-dotted ciliate bracts : 

 rays 5 to 7 mm. long : awns somewhat unequal in length, in the rays 

 3 to G, in the disk 2 to 5 (generally 3 or 4), about \h mm. long: akenes 

 slender, 4 or 5 mm. long, strigose-pubescent with capitate hairs. — Harv. 

 &, Gray in Gray, PI. Fendl. 62; Watson, Proc. Am. Acad. xxiv. 58. — 

 On sandy plains, Arizona to the Sonora coast, " California," i. e. prob- 

 ably on the Gila River ^ (Coulter, no. 330); Arizona (Palmer), Sonora 

 Alta (Coulter, no. 441 fide Hemsley) ; Sonora, Guaymas (Palmer, 

 1887, nos. 143, 654, 1890, no. 759). Dr. Palmer's Sonora specimens 

 are much more vigorous throughout than the earlier-collected specimens 

 from the Arizona desert region, but, except in size, the plants seem to be , 

 the same. 



P. ambigua. Annual, similar in habit to P. Coulteri, but smaller, 

 1 dm. or less in height : leaves thin, entire, linear or spatulate-liuear, flat, 



1 Coville, Bot. Gaz. xx. 528. 



