COMPOSITE 



119 



Coreopsis filifolia, Hook. (fig. 463). 



Achene linear or subcylindrical, narrow, biconvex, smooth on the 

 ventral aspect, obtusely muricate on the dorsal, curved outwards in 

 the middle or away from the central axis, 

 shortly two-horned at the apex, with a 

 slightly oblique, somewhat thickened basal 

 scar. 



Seed cylindrical, conforming to the shape 

 of the achene, curved ; testa thin, mem- 

 branous, white ; raphe and chalaza incon- 

 spicuous ; micropyle and hilum basal. 



Endosperm absent. 



Embryo slightly curved, filling the seed, 

 pale yellowish-white ; cotyledons linear, ob- 

 tuse, entire, plano-convex ; radicle turbinate, 

 obtuse, about one-fourth the length of coty- 

 ledons. 



FIG. 463. Coreopsis fili- 

 folia. Longitudinal sec- 



Coreopsis gigantea, Benth. (fig. 464). 



Primary root slender, tapering down- tion of achene, x 14 

 wards. 



Hypocotyl erect or ascending from a thickened base, terete, gla- 

 brous, shining, red at the base and pale green above, and more 

 slender, 2'5-4'5 cm. long. 



Cotyledons linear, obtuse, subundu- 

 late, subsucculent, flattened and slightly 

 channelled along the midrib, horizontal, 

 2'5-3 cm. long. 



Leaves simple, pinnatisect, cauline, 

 opposite, exstipulate, petiolate, subsuccu- 

 lent, glabrous ; petioles subterete, chan- 

 nelled above. 



First pair pinnatisect with two pairs 

 of lateral, and one terminal, linear, obtuse 

 segment. The ultimate leaves are tri- 

 angular in outline, two to three times 

 pinnatisect ; segments all slender, filiform, slightly channelled 

 above. 



Coreopsis laciniata, Auct. 



Primary root short, suddenly tapering, branched, annual. 

 Hypocotyl very short, tapering indistinguis.hably into the root, 

 5-8 mm. long. 



FIG. 464. 



Coreopsis qiqantea. 

 Half nat.'size. 



