\y> COMPOSITAE. 



C. leucanthemum L. O.r-et/e or While Daisy. Stem \-:! feet high, simple 

 or branched; lower leaves spatulate, petioled, more or less pinnatifid; upper 

 leaves clasping, toothed; heads large, solitary, terminating stem or branches. 

 Fields and waste places. June-September; infrequent but widely distributed: 

 Allamakee. Dubuque, Johnson, Decatur. Page, and Cerro (Soldo counties; 

 reported from Muscatine. Story, Cass, Hardin, and Woodbury counties. 



TANACETUM L. Strong-scented perennials, with alternate 1-3-pinnately 

 dissected leaves, and corymbose yellow discoid beads. Involucre hemispher- 

 ical; the scales small, imbricated. Receptuele convex. Pappus a mere bor- 

 der. Achenes angled or ribbed, terminated by a large flat disk. 



T. vulgare L. C'»nmiini 'iira*j. Stem 2-3 feet high, smooth: leaflets oblong- 

 lanceolate, cut-toothed or pinnatifid; pistillate flowers tubular, with an ob- 

 lique 3-toothed limb: pappus 5-lobed. Along roadsides and in waste places: 

 August-September: infrequent: Winneshiek. Allamakee. Johnson, and Deca- 

 tur counties; reported from Fayette and Story counties. 



ARTEMISIA L. Wokmvvood. Annua), biennial or perennial plants with en- 

 tire, toothed, lobed, or dissected, alternate leaves, and nodding heads which 

 are in panieled spikes or racemes. Involucre obovoid, imbricated, of dry 

 connivent scales. Receptacle small, naked. Heads discoid; flowers few to 

 many, tubular, perfect, or the marginal pistillate. Pappus wanting. Achenes 

 obovoid. capped by a small disk. 



* Mtuyintil flowers pistillate mid fertile; tlish-floicers perfect but sterile. 

 f Leaves piienately dissected into lutrroiehj linear lobes. 



A. caudata Mx, Biennial, stem smooth, simple, -'-4 feet high; leaves 1-3- 

 pinnately divided: the segments alternate, filiform: heads small, globose, 

 numerous, in an elongated panicle. Sandy soil, August-September; common 

 locally; Winneshiek, Muscatine, Johnson. Cerro (Jordo, Emmet, Winnebago, 

 and Lyon counties; reported from Fayette and Story counties. 



A. canadensis Mx. Biennial or perennial; stem I-'.' feet high, pubescent 

 or glabrous; leaves usually pubescent, the lower petioled and 2-pinnately di- 

 vided into linear lobes, upper leaves sessile, less divided: heads short-pedun- 

 cled, in narrow panicles, usually numerous. Dry soil: July-August; reported 

 from Woodbury and Lyon counties. 



t t Lett Mx linear, entire or the Inner .'t-elefl. 



A. dracunculoides Pursh. Perennial, stem 3-4 feet high, glabrous or can- 

 csceut when young, branched; leaves linear, entire or lower tritid; heads 

 small, numerous, in an open panicle. Dry or prairie soil: August-September: 

 frequent; Winneshiek, Floyd, Muscatine, Hancock, Dickinson, and Emmet 

 counties; reported from Fayette and Story counties. 



* * Flowers till fertile, the tintrtjinal pistillate; receptacle httirtj. 



A. frigida Willd. Whole plant silky-tanescenl; stems in tufts, (i-l.l inches 

 high; leaves pinnatifid; segments linear, 3-.">-eleft; heads small, globose, droop- 

 ing, racemose. Sterile soil; July-September; infrequent: Lyon county. 



A. absinthium L. Common. Wormwood. Shrubby, finely canescent: stems 

 1-4 feet high, much branched; leaves 1-3-pinnately divided into obovate or 

 oblong obtuse lobes, lower long petioled, the upper short-petioled or sessile, 

 the uppermost linear and entire; heads many, drooping, yellow, short-pedun- 

 cled, racemose-paniculate. Reported from Payjtte county as a rare escape. 

 * * * Flowers all fertile, the marginal pistillate; receptacle smooth. 

 t Leaves dissected. 



A. annua L. Stem 1-4 feet high, branching, glabrous, leaves :.'-3-piu- 



