APRIL, 1904. PLANTS YUCATAN^E MILLSPAUGH & CHASE. 109 



somewhat parachute-like arrangement (shown magnified 15 diameters 

 in the figure). Pappus of two chaffy scales or 2-4 inconspicuous carti- 

 laginous awns; rays persistent on the achene. Bitter aromatic herbs 

 or shrubs with broad panicles of inconspicuous heads of white flowers. 



Pappus of 2 broad scales 

 Pappus of inconspicuous awns: 



Awns 3, divergent 



Awns 2, erect 



Hysterophorus 



Schottii 

 fruticosum 



Parthenium Hysterophorus L. Sp. PL, 1402. 



A diffuse, pubescent annual with striate-sulcate stem and branches, 

 and alternate, peduncled, twice-pinnatifid, coarsely toothed leaves, 

 those of the inflorescence linear or lanceolate, entire. Inflorescence 

 of loose, open, cymose panicles; 

 branches and peduncles slender, 

 striate, hirsute. Heads 3-4 mm. 

 high, 5-6 mm. broad; ray flowers 5, 

 disk flowers numerous. Involucral 

 bracts in 2 series of 5 each, sub- 

 equal; outer ovate subacute, green, 

 3 nerved, pubescent; inner orbicu- 

 lar-obcordate with a thin, pubescent 

 margin. Corollas white, rays ob- 

 cordate; disk flowers narrowly cam- 

 panulate, the 5-toothed apex in- 

 curved. Receptacle convex; scales 

 broad, hyaline, tomentose at the 

 summit, equaling the sterile flow- 

 ers. Achene black, 1.2-1.4x2 

 mm. , obovate ; in section triangular, 



dorsal facet convex; pubescent toward the summit and down the 

 ventral angle with stipular hairs; pappus of 2 broad membranaceous 

 scales, .7 mm. high. 



Hab. Cozumel, 1885, 1886 Gaumer (Oliver); waste lands near 

 Tikul, April, 1887 Millspaugh 18; common about Merida, Valdez 12; 

 abundant near Izamal, Jan. to Dec. Gaumer 558, Chichankanab 1555, 

 1849, San Anselmo 1848; Cozumel Millspaugh PI. Utowancz 1572. 



Called ALTANIZA in Spanish. "An infusion of the leaves and 

 flowers is reputed as an emmenagogue. " (Valdez, Cuevas.) 



Parthenium Schottii Greenman Sp. Nov. 



Shrub:* Stems and branches smooth, covered with a grayish white bark, 

 branchlets slightly striate, tawny pubescent; leaves alternate, lanceolate, 

 including the petiole 5 to 10 cm. long, 1.5 to j cm. broad, gradually 

 narrowed below into a winged petiole, acute or obtuse at the apex, entire 

 or repand-dentate, hirtellous-puberulent above, the hairs arising from a 

 bulbous base, finely piibescent beneath: inflorescence in terminal and ax- 



*Italics include Dr. Greenman's original description and notes as received in manuscript; addi- 

 tional description and notes are in body type. 



