394 ON SEEDLINGS 



which has linear, entire, semiterete, thinly pilose cotyledons 

 about 8 mm. long and slightly connate at the base. The first 

 six leaves are similar but larger, longer, and more hairy. The 

 ultimate ones are long, lanceolate, pinnatisect, with linear or 

 lanceolate, pinnatifid or toothed segments, and are trinerved 

 in the lower part, giving off lateral nerves to the segments. 



The cotyledons ultimately become succulent and nearly 

 terete. Those of P. arenaria differ chiefly in their greater 

 length, measuring from 2-2-6 cm. The leaves are all linear, 

 acute, hairy or pilose, slightly furrowed along the middle, 

 entire, and differ from the cotyledons chiefly in size. The 

 cotyledons of P. gnaphalioides conform to those of P. arenaria 

 both in shape and size. The leaves are opposite and the first 

 pair resemble the cotyledons. The second pair have one to 

 two obsolete teeth on each side, and the third to the seventh 

 pairs inclusive are linear, broadest above the middle, and 

 obsoletely glandular-dentate. The cotyledons of P. callosa 

 vary from 2 - 8-3'7 cm. in length, and are glabrous, succulent 

 and terete, but otherwise conform to the type. The leaves are 

 linear, entire and alternate. The first one is thinly pilose ; 

 the second is larger and slightly furrowed along the middle ; 

 the third and fourth are deeply furrowed above and tomentose, 

 followed by two which are broader, deeply channelled above 

 and carinate beneath. The ultimate ones are felted with 

 tomentum and hoary. 



Plantago media, L. (fig. 597). 



Ovary two-celled, four-ovuled ; ovules peltate, amphitropous ; 

 A micropyle inferior. 



Fruit capsular, dry, membran- 

 ous, two-celled, two- to four- 

 seeded, dehiscing circumscissly. 



Seeds plano-convex or sub- 

 concavo-convex, peltate, small, 

 oval in longitudinal outline, with 

 FIG. 597. Plantago media. A, longi- equal obtuse ends, or the basal end 

 tudinai section of seed, x 8 : .R, radicle, slightly broader : testa thin, pale 



B, transverse section of seed, x 16. , ,., ,. , , " 



brown ; hilum a little below the 



middle on the ventral aspect, round, deeper brown than the rest of 

 the testa ; raphe tapering obliquely from the hilum. towards the 

 upper end of the seed. 



