80 PROCEEDINGS OF THE AMERICAN ACADEMY. 



San Diego Co. (Palmer, 1875, no. 200), El Rio (Lemmon, no. 78) ; 

 SoNORA, Valley of the Cocospera (Scliott), Guajmas (Palmer, 1887, 

 no. 655) ; Lower California, San Gregorio (Brandegee). Said to 

 be lemon-scented. 



P. Palmeri, Watson. A little stouter than the last : leaves mostly 

 broader and thinner, about 4 cm. long, 2 to 4 mm. wide, with 1 or 2 

 short basal setce : peduncles thicker, longer, scattered, 3 to 8 cm. long, 

 3-8-bracteate : involucre 5 to 6 mm. high, 35-50-flowered ; the bracts 

 plane, keeled below the middle : disk-pappus as in the last or merely 

 scabrous ; ray-pappus of 2 or 3 slender aristiB 3 mm. long, somewhat 

 dilated at bases : akenes 4 mm. long, strigose with clavellate, not uncinate 

 or capitate, hairs. — Proc. Am. Acad. xxiv. 58 ; Rose, Coutrib. U. S. Nat. 

 Herb. i. 338. — On foothills and in rich soil along streams, Sonora and 

 Lower California. Sonora, Guaymas (Palmer, 1887, nos. 652, 653), 

 Agiabampo (Palmer, 1890, no. 765) ; Lower California, Purissima, 

 1889 (Brandegee), La Paz (Palmer, 1890, no. 115). The Lower Cali- 

 fornian plants are smaller and with fewer-flowered heads than the original 

 Sonora specimens, but otherwise they are the same. 



-f— -1— Perennials or rarely annuals, the pappus merely scabrous. 



P. Stenophylla, Gray. Very diffusely branching from a suffruti- 

 cose base, the branches purplish, slender, glabrous, 2 or 3 dm. long : 

 leaves narrowly linear, mucronate, 3 or 4 cm. long, 2 mm, wide, or gen- 

 erally strongly revolute and scarcely 1 mm. wide, bearing two rows of 

 marginal glands and 2 or 3 pairs of long slender basal setae : heads scat- 

 tered toward the tips of the branches ; the filiform 4— 6-bracteate pedun- 

 cles becoming 5 or 6 cm. long: involucre 5 mm. high, 15-18-flowered ; 

 the 8 narrowly oblong bluntish bracts plane above, slightly keeled below 

 the middle : rays yellow, narrow : disk-pappus of 20 to 40 unequal up- 

 wardly scabrous capillary bristles 2 mm. or less in length; ray-pappus 2 

 slender smooth or minutely scabridulous awns 1^ mm. long, slightly 

 dilated below: akenes 2}j to 3 mm. long, sparingly pubescent with short 

 clavellate hairs. — Proc. Am. Acad. xxi. 393. — Hillsides and dry soil, 

 Northern Mexico. Chihuahua, Batopilas (Palmer, 1885, no. 81) ; 

 Sonora, Arroyo Hondo (Hartman, no. 216, in part), Badehuachi (F. E. 

 Lloyd, no. 402). Said to be aromatic. 



P. Hsenkeana, Schz. Bip. Perennial from a suffruticose base, or 

 annual, the stems puberulous or pubescent, ascending or somewhat de- 

 pressed, the longest 2 dm. in length : leaves pale green, linear or spatu- 

 late-linear, mucronate, 1 to 2|^ cm. long, 1^ to 4 mtn. wide, smooth or 



