600 COMPOSITAE (composite family) 



long, with a beak as long or longer. {T. Nuttallii pray, Proc. Am. Acad. 9: 

 216. 1 1874 ; Stylopappus elatus Nutt. 1. c. 433.) — !From the nojrthwestern part of 

 our range to California arid Washington. , 



10. Troximon montaniun (Osterh.) A. Nels. Perennial from a several- 

 stemrhed root?toclc; the scapes floweririg Wlien about 1 (ipa. high arid elongating 

 to 2.5 or 3 dm., woolly-pubescent beneath the involucre and^ at, the base; 

 leaves oblance,ql^te, 1-2 dm. long including the .narrqw-winged petiole, 

 glabrous at the time of flowering or nearly so, entire or some C|if the larger 

 with few teeth: flowers yellow, the Hgules little exceeding the brapts, the 

 fruiting heads about i cm. high: involucral bracts woolly-pubescent, es- 

 pecially so on the edges, in three series, the outermost ones lanceolate-acuminate, 

 the second series ovate, acuminate, exceeding the outermost, and equaling the 

 narrow inmost series: achenes 10-striate, a little less than 1 cm. long, tapeying 

 into a slender filiform beak of the ^ame length, which is crowned by the.bright 

 white pappus of aboiit the same, length. ,T. grandiflorum as to our range. 

 XAgbseris montdna Osterh. Bull, Torr. Bot Club 27: 507. 1900.)— Colorado 

 and Wyoming. 



107. TARAXACUM Hall. .Dandelion 



Perennial acaulescent Ijerbs, with pipnatifid or toothed or rarely entire 

 leaves all in a basal tuft and large heads of yellow flowers terininating usually 

 simple and naked hollow scapes. Principal bracts of the involucre nearly 

 equal, the outer much shorter and in severp,} serie^. Keceptacle flat, naked. 

 Rays 5-toothed at the truncate summit. , Achenes oblong or linear-fusiform, 

 4 or 5-angled, £j-10-iierved, somewhat spimilose above, tapering into a slender 

 beak which bearg at its summit a copious pappus of unequal persistent bristles. 



Outer calyculate bracts appressed; a diminutive alpine t>lant , , 1. T. scopulorum. 

 Outer calyculate bracts more or less spreading. ' * : 



Achenes not red. . 



Leaves deeply runcinate; outer bracts early reflexed^ ^ , 



■ The' tei*minal lobe of leaves large ■ . ' '. ' . ' ;- , ' .2. T. officinale. 



' ' Th^ terminal lobe of leaves small . . . . " . ' . 3. T. mexicanuzn. 



Leaves more or less toothed or sinuate; outer bracts tardily re- 

 ; flexed or with merely squarrose or reflexed tips. , 



■ Bracts conspicuously corniculate' 4. T. duznetonun. 



Bracts (at least the outer ones) not coi;niculate . , . 5. T. angustifolium. 



Achenes red , . . . . . . . , . . 6, T. ammbphilum. 



1. Taraxacum scopulorum (Gray) Rydb. Mem. N. Y. Bot. Gard. 1: 455. 

 1900^ Minute, leaves a,nd scape 3 cm. or less long: head '6 mm. ,6t in fruit 

 even lO mm. high, narrow, few-flowered; outer involucral brdcts lanceolate, 

 rather loose; inner somewhat corhidulate. — Highest alpine region of the 

 Rocky Mountains, Colorado to Montana^ ' 



2. Tara^cum officinale Weber, Prim. PL, Hols. 56. 1780. Root thick and 

 long, bitter: leaves oblong or sp^tulstte in outline, irregularly dentate to 

 sinuate'-pinriatifid,' from a few cm.' to, neariy 3 dlri. long, usually pubescent 

 when young arid somewhat succulent: inner bracts of the involucre linear or 

 linear-lanceolatei, acute, 10-15 mm. long; outer ones siniilar but shorter, te- 

 flexed: flowers ye^ow: pappus brownish or white, maturing into a globose 

 mass. (T. Tdraiacufn Karst.) Common Dandeii6n.^ — Naturalized from 

 Europe but finding in our range a pecuharly favorable environment, hfence 

 overrunning lawns arid meadows. 



3. 'Taraxacum mexicanum DC. Prodr. 7: l46. 1838. Vei'y similar but 

 usually Smaller: leaves narrow and the terminal lobe small: bracts few. — In- 

 digenous in the mountains ; from Wyoihiilg aild Utah to Mexico. 



4. Taraxacum dumetorum Greene, Ifitt. 4: 230. 1901. Large, the crown 

 of the root, or each of its several brariehes, bearing mostly 1 stout erect scape 

 1-3 dm. high and several upright le,ave3, some more,,than 2 drii. long; herbage 

 glabrous: leaves oblanceolate, acutish; the margin not. deeply bujt very un- 

 evenly and laciniately cut. the teeth spreading, seldqm ^t all runcinate: 

 scape under the involucre ar?ichnoid-tomentose: outer bracts 'in about 3 series. 



