4 NORTH AMERICAN FLORA [Volume; 34 



6-7 mm. broad; disk-corollas about S mm. long, slightly longer than the achene and surpassed 

 by the pappus-bristles. , 



Type locality: Jalisco. 

 Distribution: Jalisco and Tepic. 

 Illustration: H. & A. Bot. Beech. Voy. pi. 62. 



4. ARNICASTRUM Greenman, Proc. Am. Acad. 39: 115. 1903. 



Perennial herbs with opposite leaves and dichotomously branched stem. Heads radiate, 

 on elongate peduncles from the forks or at the ends of the stem. Involucre hemispheric; 

 bracts herbaceous, broad, imbricate in 3-4 series, few-veined. Receptacle naked, faveolate. 

 Ray-flowers in a single series, fertile; ligules several-nerved, indistinctly 2-3-toothed. Disk- 

 flowers numerous, fertile; corollas tubular, scarcely at all dilated at the throat, 5-lobed, sparingly 

 pubescent, not dilated at the base. Anthers linear-oblong, obtuse at the base, with lanceolate 

 tips. Style-branches hispidulous, with short triangular tips. Achenes flattened dorso- 

 ventrally, pubescent, about 20-nerved. Pappus of about 30 barbellate bristles not dilated at 

 the base. 



Type species, Arnicastrum glandnlosum Greenman. 



1. Arnicastrum glandulosum Greenman, Proc. Am. Acad. 39: 115. 



1903. 



Arnicastrum glandulosum. vestitum Greenman, Proc. Am. Acad. 39: 115. 1903. 



A perennial herb; stem about 3 dm. high, scabrous-puberulent below, glandular above, 



striate, at first simple, later dichotomously branched; leaves sessile, opposite, lanceolate, 5-8 



cm. long, entire or slightly sinuate-denticulate, rather firm, with 5-7 almost parallel ribs, 



scabrous-puberulent on both sides; involucre hemispheric, about 1 cm. high and 1.5 cm. 



broad; bracts ovate, well imbricate, puberulent, with 3-5 faint veins; ligules 12-14 mm. long, 



3-4 mm. wide, about 7-nerved; disk-corollas about 7 mm. long; achenes cuneate-oblanceolate ; 



pappus surpassing the corolla. 



Type locality: Sierra Madre, Chihuahua. 

 Distribution: Chihuahua and Durango. 



5. OLIVAEA Schultz-Bip. ; Benth. in Hook. Ic. III. 

 2:2. 1872. 



Herbs with alternate, sessile leaves. Heads solitary at the ends of the branches, radiate. 

 Involucre hemispheric; bracts in 3 or 4 series, lanceolate, herbaceous, unequal. Receptacle 

 naked, flat. Ray-flowers in a single series, fertile; ligules oblong, scarcely dentate at the 

 apex. Disk-flowers hermaphrodite, fertile; corolla-tube short, glandular-hispid, enlarged into 

 a cylindro-campanulate throat; limb 5-cleft. Anthers linear, obtuse at the base, with lanceo- 

 late tips. Style-branches flattened, with lanceolate, hispidulous appendages. Achenes com- 

 pressed, oval, 2-winged or those of the ray-flowers 3-winged. Pappus of about 10 shortly 

 plumose bristles. 



Type species, Olivaea tricuspis Schultz-Bip. 



1. Olivaea tricuspis Schultz-Bip.; Benth. in Hook. Ic. III. 2:3. 1872. 



An herb, probably paludose; stem 3 dm. high or more, erect, glabrous or papillose-puberu- 

 lent above; leaves sessile, cordate-amplexicaul at the base, narrowly lanceolate, entire, or 

 few-toothed towards the base, and sometimes 3-cleft or 3-toothed at the apex, 5-7 cm. long, 

 glabrous on both sides, 1-ribbed; heads short-peduncled ; involucre about 18 mm. broad; bracts 

 narrowly lanceolate, the inner more scarious; ray-flowers about 30; ligules about 12 mm. long; 

 disk-flowers numerous; achenes oval, flattened, glabrous, winged. 



Type LOCALITY: Guadalajara, Mexico. 

 Distribution: Southern Mexico. 

 Illustration: Hook. Ic. PI. pi. 1103. 



