COMPOSITAE (COMPOSITE FAMILY) 561 



6-9 bracts of the outer series strongly carinate, united for the lower quarter or 

 third: rays broadly or sometimes narrowly cuneate, 4-8 mm. long. Actinella 

 Richardsonii. (Hymenopappus ligulaeflorus A. Nels. Bull. Wyo. Exp. Sta. 

 28: 135. 1896; Picradenia pumila Greene, Pitt. 3: 271. 1898; P. macrantha A. 

 Nels. Bot. Gaz. 28: 130. 1899. These are reduced to varieties and some other 

 varieties added by Cockerell in his revision, cited above.) Plains; Saskatche- 

 wan and eastern Oregon to Utah and New Mexico. 



2. Hymenoxys floribunda (Gray) Ckll. 1. c. Taller and more slender than 

 H. Richardsonii, the wool at base of stem more silky ; stems repeatedly branched : 

 heads many times more numerous, less than half the size, forming a broad, 

 flat-topped inflorescence: scales of the pappus lanceolate, some slenderly acu- 

 minate, others not so. This species received some notice a few years since 

 as a possible source of rubber and became known as the COLORADO RUBBER 

 PLANT. In dry or gravelly soil; Colorado to Texas, New Mexico, and Arizona. 



3. Hymenoxys multiflora (Buckley) Rydb. Bull. Torr. Bot. Club 33: 157. 

 1906. Diffuse and at length much branched, from an annual or biennial root, 

 1-3 dm. high, with scattered small heads terminating leafy branches: leaves 

 once to thrice ternately parted into filiform lobes, not rigid: involucre cam- 

 panulate, rigid ; the outer of 7 or 8 oblong bracts, united at base : scales of the 

 pappus aristately attenuate. (Picradenia multiflora Greene, 1. c.; H. chry- 

 santhemoides multiflora Ckll. 1. c.; H. Osterhoutii Ckll. 1. c.) Dry plains; Kan- 

 sas and Colorado to Texas and Arizona. 



73. RYDBERGIA Greene 



Stout but low, upright, sparingly branched alpine woolly perennials, with 

 very large heads with long and narrow spreading yellow rays. Bracts of the 

 low-hemispherical involucre all alike, distinct, herbaceous, in several series, 

 loose, woolly. Receptacle broad and hemispherical. Rays 15-30, 2-3 cm. 

 long, linear-cuneiform, broadest and deeply 3-toothed at apex. Scales of the 

 pappus white, elongated-lanceolate, and slenderly acuminate. 



Leaves glabrate; involucre short-villous 1. R. Brandegei. 



Leaves floccose-woolly; involucre woolly . . . ... . 2. R. grandiflora. 



1. Rydbergia Brandegei (Gray) Rydb. Bull. Torr. Bot. Club 33: 156. 

 1906. Leaves glabrate, with 2 or 3 lobes toward the upper part, or some en- 

 tire, narrowly linear, only 2 or 3 on the somewhat scapiform simple flowering 

 stem (1-2 dm. high): head therefore conspicuously pedunculate, 10-12 mm. 

 high and wide; involueral bracts lanceolate: rays 12-16, 6-8 mm. long. In 

 the high mountains; southern Colorado and New Mexico. 



2. Rydbergia grandiflora (Pursh) Greene, Pitt. 3: 270. 1898. Stem 1-3 

 dm. high, very stout, floccose-woolly, somewhat glabrate in age; stem simple 

 or branching below, leafy: leaves with petiole scarious-dilated at base, lower 

 ones 2-3-ternately or quinately parted, upper with 3-5 simple lobes: invo- 

 lucre about 20-25 mm. broad, very woolly, the bracts linear: rays 30 or more, 

 12-16 mm. long. Actinella grandiflora. Alpine regions from Montana to 

 Colorado. 



74. DUGALDIA Cass. 



Tall, erect, rather stout perennials or possibly biennials, with entire or 

 parted alternate leaves which are more or less resinous-atomiferous and 

 impressed-punctate. Heads usually several and rather long-pedunculate. 

 Bracts of the involucre numerous, in 2 series, tardily re flexed. Rays fertile, 

 numerous, long, and narrow; disk-corollas with moderately long proper 

 tube. Pappus of elongated scales. Helenium in part. 



All the leaves entire . . . . . . . . . . 1. D. Hoopesii. 



Some of the leaves parted or divided 2. D. helenioides. 



1. Dugaldia Hoopesii (Gray) Rydb. Mem. N. Y. Bot. Gard. 1: 425. 1900. 

 Slightly tomentose or pubescent when young, soon glabrate; stem stout, 3-8 



ROCKY MT. BOT. 36 



