Bidens. COMPOSITE. 297 



or even 6 lines long, in the same plant either smooth with sparing bristles, or the outer becoming 

 tuberculose and rough. 



B. leucantha, Willd. Leave? of ratlicr firm texture, some undivided and ovate; the.'je 

 and tlie 3 or occasionally 5 ovate or oblong-ovate divisions evenly serrate, more or less lin- 

 eatelv veinv : heads corymbosely paniculate on rather short peduncles : rays obovate, bright 

 white, 5 to 8 lines long, rather showy. — Spec. iii. 1719; Torr. & Gray, I.e. B. striadi, 

 Sweet, Brit. Fl. Gard. t. 2;37 ; Hook. Bot. Mag. t. 3155. Coreopsis Icur.ani/icma, L. Ama>n. 

 Acad. iv. 291. C. leucantha, L. Spec. ed. 2, ii. 1282; Desc. Fl. Aut. t. 583. C. coronata, 

 ]j. 1. c. 1281, as to syn. Plum. t. .53, f. 2. — Commou iu S. Florida. (W. lud., Mex.) 



B. pilosa, 1... Stem sometimes tall, usually weak: leaves thin; leaflets 3 to 5, irregularly 

 serrate, sometimes incised, or the lower divisions occasionally 3-lobed : heads fewer and 

 scattered: rays commonly none, at most inconspicuous and yellowish-white. — Spec. ii. 832 

 (but the cited figure. Dill. Elth. t. 43, probably belongs to B. frondosa) ; Willd. 1. c. Core- 

 opsis alba, L. Spec. ii. 903 (Ilerm. Farad, t. 1241 excl. syn. Pluk.). Bidens Califomica, DC. 

 Prodr. V. 599; Torr. & Gray, Fl. ii. 354. Vai'iable, and the slender forms in warm coun- 

 tries seeming to pass into D. hipinnata. — S. California and Arizona, introduced ? (Mex. to 

 Chili, W. lud., and all tropics.) 

 * * Leaves all once to thrice 3-5-nately parted or divided into oblong or linear ultimate lobes: 



root in ours annual, 

 •f— Heads narrow: rays inconspicuous and yellowish or none: akenes long and slender, at least 

 the central ones much surpassing the involucre. 



++ Lobes of the thin leaves from oblong to lanceolate: heads slender-pcduncled. 



B. bipinnata, L. (Spanish Needles.) Primary and secondary divisions of the leaves 

 rather ovate or deltoid-lanceolate in circumscription, and the lobes mostly acute : akenes all 

 slender, the inner ones 5 to 9 lines long, outermost moderately shorter and thicker : awns 

 3 or 4, sometimes only 2. — Spec. ii. 832 ; Michx. ii. 135 ; Torr. & Gray, 1. c. — Damp 

 thickets and waste ground ; a common and disagreeable weed, New England to Florida and 

 Arizona. (Trop. Am., &c.) 



B. Bigelovii, Gray. Lobes of the leaves linear-oblong, mostly obtuse : innermost akenes 

 5 or G lines long. 2-3-awned ; outermost of half that length or less, stouter, 2-corniculate, or 

 with a pair of short awns, or even with none. — Bot. Mex. Bound. 91. B. tenuiser.ta, in part, 

 Gray, PI. Wright, i. 109. — S. W. Texas to S. Arizona, first coll. by Wright and Bigelow. 

 ++ -w- Lobes of the leaves linear. 



B. tenuisecta, Gray. A foot or two high, branched from the base, sparsely hirsute or 

 glabrous: leaves 2-3-ternately or pinnately dissected into narrow linear lobes (of a line or 

 more in width): heads on naked rather long and stout peduncles, many-flowered, 4 or 5 

 lines high in flower : involucre hirsute, especially at base : akenes glabrous, 2-awned ; inner 

 5 lines long, with tapering summit ; outermost 3 lines long, stouter and with broad summit 

 and usually short awns: rays yellow, mostly surpassing the disk. — PI. Fendl. 86. — Along 

 watercourses, Colorado, New Mexico, and Arizona ; first coll. by Fendler. 



B. Lemmoni. A foot or less high, slender, with short branches, smooth and glabrous : 

 leaves twice ternately parted into entire obtuse rather broadly linear lobes (a line or two 

 wide) ; the uppermost simply 3-5-parted, subtending the mostly sessile 5-9-flowered cylin- 

 draceous and glabrous heads: akenes nearly of the preceding, but the outer nearly like the 

 inner: rays apparently none. — S. Arizona, in Apache Pass, Lemmon. 



B. heterosperma, Gray. Slender, glabrous, paniculately much branched : leaves once 

 or twice ternately parted into filiform-linear (half-line wide) lobes: heads on slender pe- 

 duncles, few-flowered, in flower barely 3 lines long : rays apparently none : akenes 2-3-awned, 

 smooth ; the inner 4 or 5 lines long outermost only 2 lines long aiul their short awns cadu- 

 cous. — PI. Wright, ii. 90. — S. Arizona: raised from seedcoll. by Wriijht (thought to come 

 from New Mexico): rediscovered in Apache Pass by Lemmon. 



-t— H— Heads broader, many-flowered, and with comparatively large deep yellow raj's: akenes all 

 short, hardh' surpassing the involucre. 



B. procera, Don. Erect and tall from an annual or biennial root, glabrous : leaves twice 

 or thrice parted into narrow linear lobes (mostly of an inch or more in length and less than 

 a line wide): heads corymbosely paniculate: outer involucre small and inconspicuous, 



