83 



This species has a wide range of variation in tiie division and toothing 

 of its leaves, but the variations are so inconstant tliat it seems inipos- 

 sible to found specific distinfjtions upon them. In characteiizing T. 

 aureiim, Nuttall lias laid- some stress upon "lateral divisions of the upper 

 leaves subsessile," a character which means nothing, as these divisions 

 may be sessile, subsesi-ile, or petioled upon Llu^ same plant, either in T. 

 <uireiim or the 7'. trifolialiini of fJray. So far as foliage chaiacters are con- 

 cerned, serrate leaflets point to Nuttall's form, while creuately-toothed 

 leaflets stand for Gray's 7'. trifoliafitin, exclusive of his vars. uptcrnm and 

 niropurpu renin. Further confusion in leaf characters has arisen by in- 

 cluding the so-called apterous varieties, which we have restored to 

 Zlzia. An extreme variation in leaf characters, but merging completely 

 into the type through intermediate forms, is 



Var. trifoliatum C iK: K. Hot. Gazette, xii. 136, in which 

 the leaves or leaflets are crenate or crenately-toothed. — 7'. trifolia- 

 tum Gray, Manual, in part. 



Ohio to Illinois, westward to Oregon and British Columbia (Macoun). 



This seems to be the common western form of the species, as our 

 Pacific coast specimens are all distinctly this variety. From Ohio to Illi- 

 nois there is an interminable intermingling of species and variety, while 

 in Pennsylvania the specific form indistinctly represented- 



Var, involucratum. Radical leaves twice to thrice ternate; 

 leaflets as in the species: umbel with conspicuous involucre of ser- 

 rate bracts, and involucels of numerous toothed bractlets often as 

 long as the pedicels, which are 2 to 3 lines long. 



Mountain meadows, Kootenai county, Idaho, July, 1SS7 (./. W. Leiberff). 



Var. atropurpureum C. A: R. Bot. Gazette, xii. 130. Petals 

 dark-purple. — 7^. atropurpnrc/ini Nutt. 7'. tri foliation ., ww. atro- 

 purpureum Gray, Manual. 



Same range as the species. 



This variety has the leaf characters of the species, and if var. trifolia- 

 tum had been retained as a species, var. atropurpurpum would have been 

 transferred to T. aureuyn. 



In giving the range of the above group of forms it has been impos- 

 ftible to use published ranges, owing to the great confusion as to what 

 forms were intended. Discarding the apterous varieties, the true Thas- 

 piums of this group are but scantily represented in our herbaria, far more 

 so, probably, than their occurence would justify. The early spring and 

 summer flowers and fruits< of the apterous forms have probably too often 

 satisfied collectors that they had already secured good material of forms 

 which only appeared in collecting condition in late summer and autumn. 

 Therefore we can only cite such range as our material indicates, confident 



