Many, many goldenrods show combinations of characteristics of this species 

 and others, especially S. altissima. While genetic mixing is not at all unusual in 

 goldenrods, still the abundance of the plants of hybrid origin is remarkable in 

 this instance. In fact, what has been called S. rugosa var. aspera (Ait.) Fern, 

 in Oklahoma and Texas is probably merely a group of such plants that are 

 primarily S. rugosa but contaminated to varying degrees by S. altissima genes. 



5. Solidago altissima L. 



Rhizomatous perennial, usually with numerous stems (6-) 10-20 dm. tall, the 

 stems and foliage totally more or less densely covered with a fine or microscopic 

 pubescence (thus cinereous or sordid-green) and roughish; leaves of midstem 

 broadest at or below the middle, lanceolate to lance-elliptic, (3 to) 4 to 5 (to 10) 

 times as long as broad, (5-) 10-16 mm. broad, usually triplinerved (i.e., with 

 2 of the lower secondary nerves nearly as prominent as the midvein beneath and 

 ascending nearly the full length of the blade), marginally usually with a few 

 close teeth (5 to 10) on each side in the upper half to two thirds of the length; 

 head-bearing portion of stem usually dense, somewhat one-sided, with a number 

 of crowded arcuate branches each for nearly its total length crowded with 

 definitely secund head-bearing branchlets, the total number of heads usually 150 

 to 500; heads small, the involucres usually only 3-4 mm. high. S. arizonica 

 (Gray) Woot. & Standi. 



Open low areas nearly throughout Tex. but most frequent in e., s.e. and n.-cen. 

 Tex., N.M. (San Miguel, Chaves, Eddy, Socorro, Sierra, Grant and McKinley 

 cos.) and Ariz. (Coconino, Navajo, Gila, Cochise, Pima, Santa Cruz and Yavapai 

 COS.), (summer-) fall; Que., Ont. and e. U.S., w. to Wise, Neb., and Ariz. 



The plants of stream margins on the Texas Edwards Plateau (east to Kendall 

 and Uvalde cos.) and of the Trans-Pecos (Brewster, Presidio and Reeves cos.), 

 even rarely the Plains Country (Oldham Co.), have proportionately narrower leaves 

 and smoother, canescent-pubescence, only obsolete marginal teeth and usually 

 looser head-bearing portions. These are the var. canescens (Gray) M. C. Johnst. 

 Plants of Cameron Co. (Brownsville region), Texas have dark-sordid, small, 

 narrow, crowded leaves and extremely crowded heads, up to 1500 heads on some 

 stems; these are the var. pluricephala M. C. Johnst. 



6. Solidago gigantea Ait. 



Rhizomes extensive; aerial stems 5-25 dm. long, 3-8 mm. thick basally, 

 glabrous or with scattered pubescence in vertical lines on the upper part of the 

 stem; leaf transition from midstem to upper stem very gradual and involving 

 mainly diminution in size; leaves of midstem smooth, thin-membranous, glabrous 

 or with only very slight pubescence on the nervation of the undersurface, bright- 

 green, triplinerved, elliptic or lance-elliptic, 5 to 10 (to 15) times as long as 

 broad, 6-15 cm. long, (8-) 10-19 mm. broad, on each side with 10 to 20 salient 

 teeth which are spaced out evenly from apex nearly to base; upper leaves just 

 beneath the head-bearing region 4 to 8 times as long as broad, smaller and less 

 prominently toothed than the midstem leaves; head-bearing region one-sided, 

 usually fairly dense and compact in relation to the size of the plant, with a 

 number of spreading arcuate branches which nearly to their bases are densely 

 beset with the decidedly secund head-bearing branchlets; involucres about 4 mm. 

 high. Incl. var. hiophylla Fern. 



Frequent in tight moist or wet calcareous soil, along streams and in damp 

 thickets in Okla. {Waterfall), in Tex. in Plains Country and n.-cen. Tex. and 

 Edwards Plateau, less frequent s.e. to e. and s.e. Tex. (s. to San Patricio and 

 Karnes cos.) and N.M. (Lincoln and Otero cos.), (Aug.-) Sept.-Oct.; s. Can. 

 and most of U.S., s. to Ut., Colo., Tex. and Gulf States. 



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