168 ON SEEDLINGS 



Lepidium graminifolium, L. 

 Seed (fig. 171) v. ante, p. 52. 

 Seedling (fig. 173). 



Primary root slender, tapering downwards, with fibrous lateral 

 rootlets. 



Hypocotyl very short, tapering indistinguishably into the primary 



root. 



Cotyledons unequal, oblong, obtuse, entire or minutely emar- 

 ginate, petiolate, with short ascending or irregular lateral nerves 

 anastomosing with one another and discernible only by trans- 

 mitted light, glabrous, light green ; lamina of the smaller one 

 5-5-7-5 mm. long, 3'5-4'5 mm. wide ; of the larger one 7-10-5 mm. 



PIG. 171 Transverse section of seed FIG. 172. 



of Lepidium spp., x 15. Lepidium sativum, x 8. 



A, L. graminifolium. 



B, L. sativum. 



long, 4-5 mm. wide; petiole flattened above, convex beneath, 

 connate at the base, glabrous ; shorter one 4-5 mm., longer 5-5- 

 7 mm. long. 



Stem herbaceous, forming a persistent rootstock and sending up 

 flowering stems ; primary internodes undeveloped. 



Leaves simple, radical and cauline, alternate, exstipulate, petio- 

 late, alternately penninerved with the nerves running directly into 

 the teeth or more often incurved, uniting with one another, sending 

 branches into the marginal teeth and more or less distinctly reti- 

 culate, ciliate at the margins when young, glabrescent, green above, 

 paler beneath ; petioles semiterete, channelled above, dilated and 

 clasping with a usually ciliate margin at the base. 



