COMPOSITE 123 



Leaves simple, bi- to tri-pinnatisect, or by reversion pinnatisect, 

 opposite, more or less hairy on both surfaces with a line of short 

 incurved hairs along the sunk median nerve 

 of every segment, deep green above, pale 

 beneath ; petioles hairy, channelled above, 

 convex on the back, dilated and amplexicaul 

 at the base. 



First pair trifid or pinnatifid with two 

 linear obtuse segments on each side. 



Second pair with a short broadly tri- 

 angular limb, pinnatisect with the basal 

 segments largest and trifid. 



Third pair triangular, bipinnatisect, 

 with oblanceolate-linear segments. 



Fourth pair triangular-ovate, bipinnatisect with the secondary 

 segments slightly cut. 



Fifth pair triangular-ovate, bipinnatisect. 



Ultimate leaves triangular-ovate, bi- to tri-pinnatisect with the 

 ultimate segments oblanceolate-linear or oblong, entire or slightly 

 cut, acute. By reversion many of the stems and branches produce, 

 towards the top, leaves that are merely ternately pinnatisect with 

 triangular or ovate pinnatifid or merely incise -dentate segments, 

 and broad slightly toothed lobes. 



Nearer the top of these branches the leaves are ternately pinnati- 

 sect with ovate, acute incise-serrate segments. 



B. leucantha, Willd. Eeceptacle slightly concave in the early 

 stages, ultimately flat or somewhat convex, 4*25-7 mm. in diameter, 

 bearing fifty to seventy-one achenes of which thirty-seven to sixty- 

 four ripened in the specimens examined. Achenes linear, slender, 

 obtusely tetragonal, with a few ascending bristles towards the apex, 

 and terminated by two to four awns, of which two are nearly always 

 the strongest and all furnished with reflexed bristles, 6-5-13-5 mm. 

 long, -75-1-25 mm. wide, -75-1 mm. thick. 



Bidens ferulsefolia, DC. 



Hypocotyl as in B. humilis, but 2-3-5 cm. long, and light 

 green or colourless with occasionally a faint reddish tinge. 



Cotyledons linear-lanceolate, acute, entire, tapering to the base, 

 but not petiolate, fleshy, glabrous, light green, one-nerved. 



Stem herbaceous, erect, terete, finely pubescent ; 1st internode 

 about 2-4 mm. long. 



First leaves cauline, petiolate, pinnatifid, lobes 3-5 mm. long, 

 the end one, considerably the largest, acute, light green, pinnati- 



