520 COMPOSITAE (COMPOSITE FAMILY) 



lived perennial, the solitary or few stems erect from the base, 2-8 dm. high, 

 simple and leafy up to the corymbose or somewhat panicled summit, from 

 nearly glabrous below to glandular-puberulent above, the upper portion and 

 the branches glandular-hispidulous or hispid: leaves linear-lanceolate, 3-7 cm. 

 long, sessile, entire to more or less regularly spinulose-toothed, mostly glabrous 

 on both faces but marginally glandular-pubescent or ciliate: heads numerous, 

 large and showy with many purple rays; bracts of the hemispherical or sub- 

 campanulate involucre in 4 or 5 series, all with long, linear-subulate, spread- 

 ing, glandular- viscid herbaceous tips: oblong-linear achenes nearly glabrous, 

 hardly striate. (M. viscosula Rydb. 1. c. 124.) New Mexico to Wyoming. 



5. Machaeranthera Pattersonii (Gray) Greene, Pitt. 3: 63. 1896. Branched 

 from the summit of the taproot, 1-3 dm. high; stems and branches with soft 

 or cottony pubescence, or glabrate: leaves thickish, spatulate or lingulate, 

 entire or coarsely few-toothed, conspicuously hirsute-ciliate at base: heads 

 solitary or few; involucral bracts lanceolate, hispidulous as well as viscid, very 

 squarrose: rays about 30, 12-15 mm. long, bright violet: achenes glabrate. 

 (M. commixta Greene, Pitt. 4: 71. 1899.) In the high mountains; Colorado 

 and Utah. 



6. Machaeranthera latifolia A. Nels. Proc. Biol. Soc. Wash. 20: 38. 1907. 

 Perennial from short-branched caudex; stems few-several, slender, erect, 

 2-7 dm. high, minutely puberulent: leaves minutely puberulent (the upper 

 face nearly glabrous), mostly entire, rarely with a few small spinulose teeth, 

 generally 3- veined from the base and somewhat reticulate above; the basal 

 and lower stem leaves broadly oblanceolate to obovate, 2-3 cm. long, tapering 

 into a short, narrowly margined petiole; the upper stem leaves sessile or 

 nearly so, those of the inflorescence reduced and becoming bractlike: heads 

 few, corymbose, relatively large, 8-14 mm. high; involucre campanulate; the 

 bracts in 5-6 series, oblanceolate or oblong-lanceolate, the dark green acute or 

 acuminate tips ultimately reflexed, minutely glandular-puberulent : rays blue 

 with a slight violet tinge: achenes sparsely and obscurely pubescent, shorter 

 than the pappus. (M. paniculata A. Nels. 1. c.) In the canons of Utah 

 (Garrett). 



7. Machaeranthera Bigelovii (Gray) Greene, 1. c. Stems 3-7 dm. high, 

 leafy, branching above, roughish-hirsute to glabrate; the flowering branches 

 or peduncles glandular-hirsute, terminated by large showy heads: leaves 

 oblong or lanceolate, irregularly and sometimes incisely dentate, sometimes en- 

 tire ; the radical lanceolate-spatulate ; the cauline oblong to lanceolate, usually 

 with broadish partly clasping base: involucral bracts very numerous, linear- 

 attenuate or the prolonged and much recurved tips almost filiform: rays very 

 many, 15-20 mm. long. Southern Colorado to Mexico. 



8. Machaeranthera rubricaulis Rydb. 1. c. 28: 506. 1901. Biennial or 

 perhaps perennial; stems solitary or few, erect or nearly so, simple below, 

 branched above, 2-6 dm. high, terete, striate, usually tinged with red or pur- 

 ple, finely strigose-puberulent, not viscid : leaves linear or linear-oblanceolate, 

 sessile, acute, entire or dentate, scabrous-ciliolate on the margins: heads 

 corymbose-cymose; involucre 10-12 mm. high, 12-15 mm. in diameter; bracts 

 numerous, linear-lanceolate with attenuate, almost terete, squarrose tips, viscid- 

 puberulent: rays numerous, dark blue, about 12 mm. long: achenes flat, spar- 

 ingly and minutely strigose. (M. spectabilis Greene, Leaflets 1: 148. 1905; 

 M. Selbyi Rydb. 1. c. 32: 123. 1905.) Colorado. 



9. Machaeranthera viscosa (Nutt.) Greene, Pitt. 4: 22. 1899. Biennial; 

 the stems solitary or several, erect, 3-5 dm. high, usually spicate or racemose 

 in the middle, but more corymbose at summit, or not rarely wholly corymbose; 

 herbage green and seemingly glabrous, but under a lens puberulent, the 

 inflorescence and especially the involucres glandular and viscid : lower cau- 

 line leaves narrowly oblanceolate, rather remotely but sharply serrate: bracts 

 of the large and nearly turbinate involucre in 5 or 6 series and closely imbri- 

 cated, the green herbaceous tips long and narrow, closely reflexed and very 

 viscid: rays purple or violet, 18 or 20. Montana to Colorado and westward. 



10. Machaeranthera canescens (Nutt.) Gray, PI. Wright. 1: 89. 1852. 



