422 



ON SEEDLINGS 



Embryo curved and following the vertical ridge of the seed, and 

 equal in length to this circumference ; cotyledons linear, obtuse, 



FIG. 6Q9.Chenopodium Bonus-Henricus, x 8. A, seed. B, vertical 

 section of seed. C, transverse section of seed : H, hilum ; R, radicle ; 

 C, cotyledon ; P, P, endosperm. 



plano-convex, lying in narrow plane of the seed ; radicle cylindrical, 

 obtuse, about equal in length to the cotyledons, with its tip close to 

 the hilum as are the tips of the cotyledons. 



Seedling (fig. 610). 



Primary root tapering downwards, and giving off fibrous lateral 



rootlets. 



Hypocotyl erect, terete, 

 glabrous, red, 1-2 cm. long. 



Cotyledons linear-lanceo- 

 late, obtuse, entire, tapered 

 gradually into a long petiole, 

 which is connate with its 

 fellow at the base, forming a 

 little cupule from which the 

 plumule emerges, glabrous, 

 green, traversed longitudin- 

 ally by a distinct midrib, 

 about 3 cm. long including 

 the petiole ; petiole flattened 

 above or slightly grooved, 

 convex on the back. 



Stem herbaceous, de- 

 veloped when about to flower ; 

 primary internodes unde- 

 veloped. 



Leaves simple, radical and 

 cauline, alternate, exstipulate, 



petioiate, glabrous, more or less farinose, especially on the under 

 side, the petioles and the young leaves, alternately and ascendingly 



FIG. 6W.Chenopodium Bonus-Henricus. 

 Nat. size. 



