78 PROCEEDINGS OF THE AMERICAN ACADEMY. 



lous above, 1| to 4^ cm. long, li to 3 mm. wide, with 4 or 6 irregular 

 rows of conspicuous glands beneath, and 4 to 10 pairs of basal setae: 

 heads scattered or subcorymbose toward the tips of the upper branches ; 

 the slender peduncles i to 2 cm. long, generally with 2 approximate sub- 

 median bracts and often a third one above : involucre 5-bracteate, 5 mm. 

 high, 10-12-flowered ; the purplish bracts linear, acuminate, glabrous: 

 rays small, yellowish : pappus 10-25 (sometimes reduced even to 3 or 4) 

 upwardly scabrous unequal rufescent bristles slightly or not at all dilated 

 below, the longest about 4 mm. long : akenes compressed, 2 to 2J mm. 

 long, setulose with rufescent hairs. — Nov. Gen. et Spec. iv. 262, t. 392 ; 

 DC. Prodr. v. 99 ; Baker in Mart. Fl. Bras. vi. pt. 3, 288 ; Hierouymus 

 in Engler, Bot. Jahrb. xix. 60. P. stricta, Willd. in Less. Linnasa, vi. 

 710, in syn. Lorentea polycephaln, Gardn. in Hook. Loud. Journ. Bot. 

 V. 240 Jide Baker 1. c. — A common South American species extending 

 nortli to Guatemala. Guatemala, Chupadero, Depart. Santa Rosa 

 (Heyde & Lux in Exsic. J. D. Smith, no. 3806) ; Panama (Seemann). 

 Both these specimens have the pappus-bristles greatly reduced in number, 

 but otherwise they seem identical with the true South American plant 

 as figured with the original description. A specimen from Nicaragua 

 (Chas. Wright) which Dr. Gray thought might be a form of P. Ber- 

 landieri, is too old for determination, but it may belong here. 



Var. Schottii. Much more slender with very slender diffuse 

 branches and small leaves : heads scattered and solitary in the axils, on 

 capillary 3-4-bracteate peduncles 2 or 3 cm. long : involucre pale, 4 mm. 

 high : pappus hardly equalling the akene. — Yucatan, Maxcanu (Schott, 

 1865, no. 666). Type in Herbarium of Field Columbian Museum. 



-1— -1— Perennial, stems suberect branching from near tiie base. 



P. diffusa, Hook. & Arn. A decimeter or so high, with a few sub- 

 erect branches rising from the slightly suffruticose base, these branches 

 simple or with short densely leafy branchlets above ; stems angulate or 

 subterete, smooth or puberulent, densely clothed with ascending leaves : 

 leaves linear, thick, submucronate, with prominent midribs, smooth or 

 scabrous on both surfaces, the larger 3 or 4 cm. long, 2| or 3 mm. wide, 

 with or without 2 or 4 irregular rows of dots beneath, and with 5 to 10 

 pairs of setae below the middle (set;ip reduced or sometimes wanting on 

 the upper leaves) : peduncles capillary, from tl#e upper axils, 1 to 4 cm. 

 long, with 2 to 6 scattered subulate-ovate bracts : involucre 4 to 6 mm. 

 high, of 5 oblong acutish or obtuse bracts, 10-12-flowered: rays linear-, 

 oblong, yellow, 6 or 7 mm. long: pappus of 10 to 20 (rarely only 4 or 5) 



