250 American Midland Naturalist Monograph No. 2 



2. Heads in panicles, racemes, or axillary clusters; bracts of the involucre 

 not longitudinally striate. 



3. Heads in small axillary clusters or short racemes. 

 4. Stem pubescent; achenes glabrous at maturity. 



5. Rays cream color or nearly white; involucres 3-5 mm. high; wooded 



slopes and ridges, local. Aug.-Oct. White Goldenrod 



S. bicolor L. 



5. Rays orange-yellow; involucres 5-6 mm. high; wooded slopes and 



ridges, rare. La Salle Co S. hispida Muhl. 



4. Stem glabrous; achenes puberulent; leaves sharply serrate. 



6. Stem more or less glaucous, terete; leaves sessile, lanceolate; woods, 



throughout 111., except the w. and n.w. counties. Aug.-Oct. 



Wreath Goldenrod S. caesia L. 



6. Stem angled, not glaucous; leaves ovate, the petioles winged; 

 woods, throughout 111. Aug.-Oct. [S. flexicaulis L.] Broad- 

 leaved Goldenrod S. latijolia L. 



3. Heads mostly in terminal panicles or racemes. 



7. Branches of the panicle spreading or recurved, the heads distinctly 

 secund. 



8. Stem glabrous or nearly so (rarely sparsely villosulous) . 

 9. Branches of the inflorescence pubescent. 

 10. Stem terete. 



11. Leaves pinnately veined, oval or elliptical, thin, serrate, 

 sparsely hirsute along the veins beneath, the lower with 

 margined petioles; racemes few, divergent, slender; rays 

 1-6; wooded slopes and ridges, common. Aug.-Oct. 

 Elm-leaved Goldenrod S. ulwifolia Muhl. 



11. Leaves (at least the median and lower) more or less 

 distinctly 3-ribbed, lanceolate, sessile, sharply serrate, 

 glabrous on both sides or sparingly hirsute or hirtellous 

 on the veins beneath, the margins scabrous; inflores- 

 cence a dense pyramidal panicle; rays 7-15; moist 

 ground, common. Aug.-Oct. [S. gigantea Ait.; ^V. gi- 



gantea var. leiophylla Fern.} Late Goldenrod 



_ S. serotina Ait. 



10. Stem sharply angled; leaves oval or lanceolate, thick, gla- 



brous beneath, strongly scabrous above, serrate or entire, 

 acute; heads 15-20-flowered, the involucres 3-4.5 mm. 

 high; bracts obtuse; wet ground. Aug.-Oct. Spreading 



Goldenrod S. patula Muhl. 



9. Branches of the inflorescence glabrous or merely hirtellous. 



11. Panicles usually longer than broad, the branches erect or 



ascending; heads 4-6 mm. high; rays 2-8; bogs and 

 swamps, local; known from Cook, Kane, La Salle. Peoria, 

 and Woodford counties. Aug.-Sept. \S. tieglecta T. & G.; 



S. uliginosa of auth., not Nutt.} Swamp Goldenrod 



S. uniligulata (DC) Porter 



