138 ON SEEDLINGS 



above, green or more often violet beneath, and very hairy, palmately 

 five- to seven-nerved at the base and alternately penninerved upwards ; 

 petioles semiterete, channelled above, dilated and amplexicaul at the 

 base, densely hairy or villous. 



No. 1. Cordate, obtuse, five-nerved, distantly dentate with tri- 

 angular, mucronate teeth. 



Nos. 2 and 3. Cordate, acute, five- to seven-nerved at the base, 

 coarsely dentate with occasional smaller intermediate teeth, deeply 

 auricled at the base ; teeth mucronate. The ultimate leaves differ 

 little except in size, 



Senecio erucaefolius, Huds. 



Achene oblong-cylindrical, narrowed at the very base, constricted 

 immediately beneath the base of the pappus, pubescent with lines 

 of short ascending hairs ; pappus copious, with thinly puberulous 

 hairs. 



Seed oblong, obtuse, narrowed slightly to the base, smooth, pale 



FIG. 475. Senecio eruccefolius. Two stages of seedling. 



brown ; hilum small, basal ; raphe forming a deeper brown line along 

 one side to the apex of the seed. 



Endosperm absent. 



Embryo colourless ; cotyledons as in S. cruentus ; radicle stout, 

 obtuse, close to the base of the seed, slightly narrower than the 

 cotyledons, but about equal in length. 



Seedling (fig. 475). 



Hypocotyl glabrous, 5-8 mm. long. 



Cotyledons immediately after germination small, oval, obtuse or 

 rounded at both ends, entire. After they have become three or four 

 times as large, they are still oval but emarginate. Finally they 

 become rotund, deeply emarginate, and 5-7 mm. long and wide. 



The apex has three or four large open pores, which are visible 

 under the microscope at an early stage and continue more or less 

 distinct till the cotyledon becomes old and thick. 



The cotyledon is trinerved immediately after germination. The 

 lateral nerves and midrib are distinct in both lamina and petiole, 

 and are continued down to the vascular bundles of the hypocotyl ; 



