Bidens. COMPOSITE. 295 



lineatis," &c., is taken) & Vaill. ; Walt. Car. 215; name best not restored. Diodonia mitis, 

 aurea, & leptoplujlla, Nutt. Trans. Am. Phil. Soc. 1. c. 3G0. — Wet cjrovind, Virginia to Florida. 

 The original C. aurea is a form with some of the upper leaves lanceolate an-l entire, low- 

 ermost of 3 leaflets. Extreme forms are : var. subintegra, Torr & Cray, with all or most of 

 the leaves undivided and lanceolate (C. arguta, Pursh, Fl. 567, & C amhiuna, Xutt. Jour. 

 Acad. Philad. yii. 75) ; var. leptophijUa, Torr. & Gray, 1. c., with leaves or their few divisions 

 elongated linear, only a line or two wide (Diodonla leptophijlln, Nutt. Trans. Am. Pliil. Soc. 

 1. c), a brackish coast form; and var. incisa, Torr. & Gray, 1 c, with nearly all the leaves 

 3-7-divided and the divisions incised or coarsely serrate (C mitis, Michx. Fl. ii. 138, & the 

 C. coronatu of herb. Linn.), the form which approaches or passes into the following. 

 C. trichospertna, Mkhx. Glalu-ous or nearly so, a foot or two (rarely 3 to 5) high: 

 lea\es almost all 3-5-divided into lanceolate coarsely serrate or pinnately incised divisions : 

 rays oval-obovate, two-thirds to three-fourths inch long : akcnes narrowly cuneate-oblong, 

 sparsely hairy or glabrate, about 4 lines long and barely a line wide, or the outer somewhat 

 broader and shorter, bearing a pair of strong subulate pointed erect teeth, commonly equal 

 in length to the breadth of the summit of the akene. — Fl. ii. 139 ; Torr. & Gray, Fl. ii. 340. 

 C. aurea, Lindl. Bot. Reg. t. 1228. DiocJonta coromita,'Nntt. \. c. — Wet ground, coast of 

 Mass. to Virginia and N. E. Georgia. Also shoJ-e of L. Erie to Illinois; where is a 



Var. tenuiloba,. Tall, much branched : divisions of the leaves from narrowly lanceo- 

 late to linear : al^eiies smaller (outer barely S lines long), and with shorter somcwliat spread- 

 ing teeth : approaching C. aurea. — Peat bogs, Indiana and Illinois, Vase/j, Stewart, &c. 



-»— -f— Heads radiate: rays golden yellow, sometimes inch long: akenes obovate, very flat, with 

 very thin margins hispid-ciliatc : leaves all 3-7-divided or parted; the divisions sen-ate, incised, 

 or some again cleft: herbage somewhat pubescent or glabrous. (Hj'brids of these witli Bidens 

 froiiuosa or others are not uncommon.) 



C. aristosa, Michx. Stem 1 to 3 feet high : divisions of the leaves lanceolate, acuminate ; 

 bracts of the outer involucre 8 to 10, barely ciliate, not surj)assing the inner: akene with a 

 pair of slender upwardly scabrous awns of 'ts own length, or these rarely wanting. — Fl. 

 ii. 140; Torr. & Gray, 1. c. ; Hook. f. Bot. Afag. t. 6462. C. aristata, Willd. Spec. iii. 2253. 

 Diodonta aristosa, Nutt. 1. c. — Swamps, ]\Iichigan to Iowa, Mi.ssouri and W. Louisiana : 

 Soutliwestward with the var. mvtica (the awns wanting), there disposed to pass into the 

 next. 



C. involucrata, Nutt. Heads rather larger : bracts of the oitter involucre t2 to 20, mostly 

 surpassing the inner, slender, hispid on the back and margins : akenes with 2 sliort acute 

 teeth. — .Jour. Acad. Philad. vii. 74 ; Torr. & Gray, 1 c. Diodonta involucrata, Nutt. Ti'ans. 

 Am. Phil. Soc. 1. c. — W. Illinois to Kansas and Texas. 



H— -I— -)— Heads without rays, or rarely a rudimentary one, short-pedunculate: disk dull j-ellow : 

 outer involucre of 3 to 5 irregular foliaceous bracts, some or most of them surpassing the head: 

 herbage glabrous or nearly so: leaves slender-petioled. 



C. bidentoid.es, Nutt. Rather stout, 1 to 4 feet high, with ascending l>ranches : leaves 

 undivided, lanceolate, acuminate, serrate, tapering at base into the long petiole : heads ob- 

 long, half to three-fourths inch long, and outer involucral bracts sometimes inch and a half 

 long, resembling uppermost leaves ; bracts of inner involucre with somewhat pctaloid mar- 

 gins and tips • akenes cuneate-linear, 4 or 5 lines long, more or less exceeding the two setiform 

 upwardly hispidulous awns, rarely vestiges of awns from lateral nerves. — Torr & Gra}^ Fl. 

 ii. 339. Diodonta {Ilcterodonta) bidentoides, Nutt. Trans. Am, Phil. Soc. vii 361. — Jluddy 

 shores of Delaware River and Bay, from above Philadelphia, first coil by JVutlaU. 



C. discoidea, Tour. & Gray, 1. c. Slender, with widely spreading branches, a foot or two 

 high: leaves membranaceous, irregularly serrate; uppermost undivided and rliomboid- 

 lanceolate ; lower divided into 3 sessile or petiolulate leaflets : heads campanulate, a quarter- 

 inch high ■■ akenes narrowly cuneiform, 2 or 3 lines long, tlie two subulate teeth rather than 

 awns mostly shorter than the width of its summit. — River borders and swamps, Connecticut 

 and N. New York to Ohio, Virginia, and Te.xas. 



113. BIDENS, Tonrn. Bur-Marigold. (Lat. Wr7ew.<r, with two teeth or 

 prongs: name from the adjective, i. e. planfa bidens, therefore feminine.) — Herbs, 

 of wide distiibution, chiefly American; with opposite either smiple or compound 



