COMPOSITAE. 



VOL. III. 



49. Solidago Houghtonii T. & G. 



Houghton's Golden-rod. Fig. 4261 . 



Solidago Houghtonii T. & G. ; A. Gray, Man 

 211. 1848. 



Stem slender, glabrous below, sparingly 

 pubescent above, i-2 high. Leaves linear, 

 the basal and lower ones petioled, 4'-5' 

 long, 2"-4" wide, 3-nerved, entire, acute at 

 each end, the upper smaller, sessile, slightly 

 conduplicate, otherwise similar, the upper- 

 most small and bract-like; heads about 3" 

 high, few, in a small corymbose cyme, 20- 

 3o-flowered ; involucre broadly campanu- 

 late, its bracts oblong, obtuse; achenes gla- 

 brous, 4-5-nerved. 



In swamps, north shores of Lakes Michigan 

 and Huron, and in Genesee Co., N. Y. Re- 

 corded from Lake Superior. Autumn. 



23. EUTHAMIA Nutt. Gen. 2 : 162. 1818. 



Erect, paniculately-branched herbs, perennial by long rootstocks, with linear or linear- 

 lanceolate, entire, sessile, i-S-nerved punctate leaves, and very numerous small heads of both 

 tubular and radiate yellow flowers, clustered in the large corymbose, convex or nearly flat- 

 topped inflorescence. Bracts of the involucre obtuse, imbricated in several series, appressed, 

 somewhat glutinous. Receptacle flattish, fimbrillate, or pilose. Ray-flowers pistillate, usually 

 more numerous than the disk-flowers, the rays small. Disk-flowers perfect. Anthers obtuse 

 at the base. Style-branches with lanceolate appendages. Achenes top-shaped or oblong, 

 villous-pubescent. [Greek, referring to the clustered heads.] 



About 10 species, natives of North America. Type species: Euthamia graminifolia (L.) Nutt. 

 Leaves distinctly 3-s-ribbed ; heads 2O-3o-flowered. 



Involucre 2"-2y 2 " high, the bracts yellowish. i. E. graminifolia. 



Involucre less than 2" high, the bracts with appressed gre.en tips. 2. E. floribunda. 



Leaves i-ribbed, or with a pair of indistinct lateral nerves; heads rarely more than 2o-flowered. 

 Involucre 2 l / 2 ' '-3" high; southwestern species. 



Leaves 2" -4" wide ; involucre scarcely viscid. 3. E. leptocephala. 



Leaves i"-2 l / 2 " wide; involucre very viscid. 4. E. gymnospermoides. 



Involucre 2" high, or less. 



Leaves i"-2j" wide; involucre campanulate. _ 5. E. tenuifolia. 



Leaves less than i" wide; involucre subcylindric. 6. E. minor. 



i. Euthamia graminifolia (L.) Nutt. 

 Bushy, Fragrant, or Flat-topped Golden- 

 rod. Fig. 4262. 



Chrysocoma graminifolia L. Sp. PI. 841. 1753. 

 Solidago lanceolate L. Mant. 114. 1767. 

 S. graminifolia Salisb. Prodr. 109. 1796. 

 E. graminifolia Nutt. Gen. 2: 162. 1818. 

 E. Nuttallii Greene, Pittonia 5 : 73. 1902. 

 E. camporum Greene, loc. cit. 74. 1902. 



Stem paniculately much branched, or rarely 

 simple, glabrous or roughish-pubescent, 2-4 

 high. Leaves numerous, linear-lanceolate, 

 acuminate or acute at each end, i'-s' long, 

 2"-4" wide, 3-5-nerved, minutely rough-pubes- 

 cent on the margins and nerves of the lower 

 surface ; resinous dots few ; heads 2"-2i" high, 

 sessile in capitate clusters arranged in a flat- 

 topped compound corymb ; involucre ovoid- 

 campanulate to - subcylindric, its yellowish 

 bracts oblong or oblong-lanceolate, slightly 

 viscid; rays 12-20; disk-flowers 8-12. 



In moist soil, fields and roadsides. New Bruns- 

 wick to Saskatchewan, Alberta, Florida, Nebraska 

 and Wyoming. Fragrant. July-Sept. 



