Solidago Compositae 917 



E. Leaves not triple-nerved, more or less pinnately veined, although 

 some of the leaves may have short and faint lateral veins, 

 a. Stems glabrous or more or less pubescent above the middle; pappus 

 of bristles longer than the achenes. 



Stems strongly angled, at least below the middle, glabrous; leaves 

 usually very thick and the upper surface strongly scabrous, 

 the hairs (under a 28 diameter magnification) appearing 

 stout, conical, and arising from a callous base; plants of a 



springy or wet habitat 15. S. patula. 



Stems terete (strongly striate in Solidago rugosa var. celtidifolia) . 

 Plants flowering mostly from the first of July to the last of 

 August, with large rootshoot leaves at flowering time, these 

 often with blades 15 cm long on petioles of equal length; 

 upper cauline leaves linear or narrowly elliptic and entire or 

 with only a few teeth 11a. S. juncea. 



Plants flowering mostly from the last of August through Sep- 

 tember, usually lacking the rootshoots at flowering time; 

 upper cauline leaves not of a linear type, usually short- 

 elliptic or short-lanceolate and serrate on both margins. 

 Leaves pubescent beneath, sharply serrate to the inflorescence; 

 achenes pubescent. 

 Blades of leaves usually firm to thick, antrorsely scabrous 

 above with stout projections much less than 0.5 mm 

 long, these arising from a callous base making the 

 upper surface very rough to the touch, both surfaces 

 of the blade more or less strongly pitted, that is, with 

 the areas between the veinlets more or less sunken, 

 giving the appearance of deeply hammered metal ; plants 

 of wet places, stoloniferous. 



Leaves tapering at the base 17. S. rugosa. 



Leaves rounded at the base. 



Blades more than two and a half times as long as wide; 



pedicels mostly with 1-5 bracts 



17a. S. rugosa var. aspera. 



Blades less than two and a half times as long as wide; 



pedicels mostly with 3-9 bracts 



17b. S. rugosa var. celtidifolia. 



Blades of leaves usually thin, pubescent above with scat- 

 tered, curved hairs 0.5-1 mm long, rarely glabrous; 

 leaves mostly long-acuminate or short-acuminate at the 

 apex, tapering to a sessile or subsessile base, neither 

 the upper nor the lower surface having the areas be- 

 tween the veinlets sunken; plants of dry soil, not 



stoloniferous 16. S. ulmifolia. 



Leaves glabrous beneath; basal leaves lanceolate, sometimes 

 broadly so, the cauline ones similar in shape but narrower 

 and quickly diminishing in size upward, the margins entire 

 or some more or less serrate; fresh leaves usually with a 

 greasy texture; achenes glabrous or strigose. 



Axis of the inflorescence pubescent 18. S. uniligulata. 



Axis of the inflorescence glabrous 



, * , , . . . 18a. S. uniligulata var. levipes. 



