494 COMPOSITiE. Taraxacum. 



* Exterior involucral scales spreading or squarrose. 



1. T. Dens-leonis (Desf.) : at length glabrous; leaves unequally and 

 acutely runcinate, the lobes toothed anteriorly; scales of the involucre not 

 comiculate, the exterior reflexed ; achenia muricale at the summit. — DC. ! 

 prodr. 7. p. 145. T. officinale, Vill. ; Koch, syn.Jl. Germ. S^- Helv. p. 428, 

 var. a. Leontodon Taraxacum, Linn. ; En^'i. hot. t. 510 ; Pursh, fi. 2. 

 p. 497 ; Ell. sk. 2. p. 250 ; Hook. ! Jl. Bor.-Am. 1. p. 296 ; Darlingt.! fl. 



Cest. p. 443. , -D . 



Pastures, &c., naturalized nearly throughout the United States ! Proba- 

 bly native in the Northern States, and throughout British America on both 

 sides of the Rocky Mountains. Hook. April-Sept.—" When the heads of 

 flowers first expand, the pappus is nearly sessile; as soon as the florets 

 shrivel, the inner series of the involucre closes for a short time, in a cylindri- 

 cal form ; the beak of the achenia then becomes suddenly elongated, the 

 whole involucre is reflexed, and the elevated pappus displayed in a globular 

 head." Darlinot. — The following species (the characters of which we copy 

 from chiefly De CandoUe, who keeps them distinct), as well as nearly all 

 the genuine Taraxaca, are not improbably correctly viewed^ by Fries, Koch, 

 and other excellent botanists, as mere varieties of this, the Common 

 Dandelion. 



2. T. latilohum (DC.) : leaves runcinate, glabrous above, sparsely hairy 

 (especially on the midrib) beneath ; the lobes broadly triangular, toothed an- 

 teriorly, crowded ; scape glabrous ; scales of the involucre not comiculate ; 

 the exterior reflexed-spreading ; achenia muricate throughout. DC! L c. 



Newfoundland, Pylaie /—Very [too] near T. Dens-leonis. DC. 



3. T. ceratophorum (DC.) : leaves glabrous, sinuate-toothed or riancinate ; 

 scapes glabrous, when young tomentose at the apex ; scales of the involucre 

 all erect, furnished with a callous horn below the apex ; achenia mucronate 

 at the apex, as long as the beak. DC. I. c. — Leontodon ceratophorum, 

 Ledeb. Jl. Alt. 4. p. 149, S^- ic. pi. Ross.- Alt. 1. ^ 34. 



Unalaschka (and Kamtschatka).— Lobes nf the leaves various in size ; the 

 larger triangulate. Head twice as large as that of T. Dens-leonis. DC. 



* * Exterior involucral scales apprcssed. 



4. T. jJahistre {DC .) : glabrous; leaves lanceolate, sinuate or somewhat 

 runcinate, as long as the scape; scales of the involucre not comiculate; the 

 exterior lanceolate, acute; achenia spinellose-muricate at the apex, one-half 

 or one-third the length of the beak. DC. ! fi. Fr., &f prodr. I. c— Leon- 

 todon palustre, SmHh, fi. Brit. 2. p. 823 ; Engl. hot. t. 553 ; Hook. .' fl. 

 Bor.-Am. 1. p. 296. L. Taraxacum [:i. salinum, E. Meyer, pi. Lahrad. 

 p. 58. Taraxacum montanum, ISutt. ! in trans. Amer. phil. soc. I. c. p. 430, 

 not of -DC. 



British America ! from Labrador and Hudson's Bay to the Pacific. Also 

 amonfT the Rocky Mountains, in somewhat saline situations on the Platte, 

 and in the highest vallies of the Colorado of the West. Nuttall! — Varies 

 greatly as to the shape and toothing of the leaves. 



5. T. hirsutum (Hook.) : hirsute throughout ; leaves pinnalifid ; the une- 

 qual lobes acuminate, remote; scales of the involucre erect, appressed, 

 clothed with fulvous hairs. Hook.! fi. Bor.-Am. 1. p. 296 (under Leonto- 

 don); DC. I.e. p. 149. 



Menzies' Island, and sandy banks of the Oregon, Douglas, Dr. Scouler. 



