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THISTLE FAMILY 841 



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a strong basal callus. Pappus double, the inner of 2-12 slender or capillary 

 bristles equalling the slender corolla, the outer of alternating short thin paleae. 



1. H. pluriseta A. Gray. Shrub 3-5 dm. high, with white bark: leaves 

 long-petioled; blades lanceolate, deltoid or hastate, 5-10 mm. long, dentate or 

 entire; heads about 20-flowered, 8-10 mm. high; bracts with spreading tips, 

 glandular-puberulent, the outer herbaceous, the inner chartaceous; pappus of 



10-12 bristles and as many narrow acute chaff. Arid regions: s Calif. — Nev 



s Ltah — Ariz. L. Son, Ap-My. 



3, EUPATORIUM L, Joe-pye Weed, "Thoroughw^ort, Boneset 



White Snake-root. , 



Ours erect branching perennial herbs, with opposite or verticillate, often 

 punctate leaves, cymose-paniculate heads, and white to purple flowers. Invo- 

 lucre oblong to hemispheric, its bracts imbricate in 2-several series. Recep- 

 tacle from flat to conic, naked. Ray-flowers none. Corolla of the disk-flowers 

 regular, with slender tube and 5-lobed limb. Anthers obtuse at the base, ap- 

 pendiculate at the tip. Style-branches elongate, flattened, or thickened above, 

 stigmatic at the base. Achenes 5-anglcd, truncate at the apex. Pappus simple, 

 of numerous capillary scabrous bristles. 



Leaves verticiUate in whorls of 3's; flowers pink or rose-colored. 



Leaf-blades lanceolate, acuminate, strongly reticulate and rugose. 1. E. Bruneri 

 Leaf-blades broadly ovate, acute, neither strongly reticulate nor rugose. 



Leaves opposite; flowers wliite or slightly tinged T^ith pink. * • ' " ""*' 



Achenes hispidulous on tlie angles. 



Bracts unequal in length, distinctly ribbed only towards the base. 



T^ ^ ..11 , . , , , 3. ^. texense. 



Bracts essentially equal in length, strongly ribbed to near the apex. 



, , 1,1,1 , 4, E. arizonicum. 



Achenes merely glandular-puberulent or glabrate. 5. E. occidentals 



1. E. Bruneri A. Gray, Stem more or less canescent, 5-15 dm. high; leaf- 

 blades serrate, scabrous above, velutinous beneath, 10-15 cm. long; bracts more 

 or less purplish, the outer ovate, pubescent, the inner linear-oblong, glabrous, 

 all rounded or obtuse at the apex; heads nearly 1 cm. high. E. atromontanum 

 A. Nels. £. Rydhergii Britton. Moist soil: Sask.— la.— Colo.— Utah — B.C. 

 Plain — Sxihmoni. Jl-S. 



2. E, znaculatum L. Stem scabrous or pubescent, at least above, 5-20 

 dm. high, striate, often spotted with purple; leaves ovate or the upper ovate- 

 lanceolate, acute, coarsely serrate, puberulent beneath and often pubescent on 

 the veins above; bracts purplish, the outer ovate, rounded at the apex, the inner 

 linear-oblong, acutish; heads about 1 cm. high, Moist soil: N.Y. — Ky. — N.M, 

 — Sask. Plain, Au-S. 



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3. E, texense (T. & G.) Rydb. Shrubby at the base; stem 5-10 dm. 

 high, puberulent; leaf-blades ovate, deltoid or cordate, coarsely dentate, triple- 

 nerved, more or less scabrous on both sides, 2-5 cm. long; inflorescence corjmbi- 

 form-paniculate; heads 8 mm. high; bracts in about 2 series, only slightly imbri- 

 cate, lanceolate, acute, puberulent; flowers about 12. Rocky hills: Tex. — Colo. 

 ■ — Ariz, Son, — SubmonL Jl-S. 



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4. E, arizonicum (A. Gray) Greene. Stems 3-7 dm. high, from a woody 



cespitoso caudex, yellowish green, finely puberulent; leaf-blades ovate or cordate, 

 2-5 cm. long, dentate, with small obtuse teeth, triple-nerved, minutely scabrous; 

 inflorescence panirulate; heads about 7 mm. high; bracts In 2 series, practically 

 equal in length, scabrous-puberulent, lanceolate. E, occidentale arizonicum A. 

 Gray. Canons: s Utah— N.M.— s Calif. L. Son, Au-0. 



6. E. occidentale Hook. Stems 2-5 dm. high, finely puberulent or glabrate; 

 leaf-blades ovate, rounded or truncate at the base, 2-5 cm. long, triple-nerved, 

 minutely scabrous-puberulent, more or less dentate; heads paniculate, 7-8 mm., 

 high; bracts in two series, equal, puberulent, faintly ribbed. Rocky places: 

 Wash,— Ida —n Utah— Calif. Son, Jl-S. 



