160 ON SEEDLINGS 



with the midrib ; glabrous, glaucous-green on both surfaces, amplexi- 

 caul at the base. 



1st and 2nd pairs linear oblong, cuspidate, somewhat constricted 

 above a broad, amplexicaul base, and again dilated above the 

 middle, entire. 



3rd pair oblong, cuspidate, amplexicaul, less conspicuously 

 constricted above the base or not at all, entire. 



Camelina sativa, Crantz. 



Hypocotyl short, erect, terete, glabrous, 3-5 mm. long, light 

 green or colourless. 



Cotyledons oval-oblong, obtuse, entire, glabrous, rather fleshy, 

 shortly petiolate, light green, with no apparent venation. 



Stem with primary internodes undeveloped. 



First leaves simple, radical, alternate, obovate-oblong, obtuse, 

 crenate, exstipulate, petiolate, hairy, green, pinnatinerved ; the first 

 leaf is often entire ; petioles rather long, hairy, channelled on the 

 upper side. 



Diplotaxis erucoides, DC. 



Hypocotyl short, terete, hardly appearing above the surface of 

 the soil. 



Cotyledons oblong, obtuse, emarginate, petiolate, rather fleshy, 

 glabrous, green, indistinctly one-veined. 



Stem with primary internodes undeveloped. 



First leaves simple, radical, alternate, obovate-oblong, obtuse, 

 exstipulate, petiolate, hairy, green, pinnatinerved ; the first leaf is 

 entire, the second leaf crenate or almost lobed. 



Brassica nigra, Boiss. 



Siliqua sessile, terete, or subtetragonal, beaked, many-seeded ; 

 beak often one-seeded and indehiscent. 



Seed globose or oblong-globose, often appearing angled from 

 the unequal shrinking of embryo and testa in malformed or imma- 

 ture seeds, small ; testa deep brown or almost black when the seed 

 is perfectly matured ; hilum small, occupying one end of the seed 

 when the latter is oblong-globose ; chalaza contiguous to the 

 hilum, and forming a dark-coloured spot ; raphe none ; micropyle 

 close to the hilum. 



Embryo large and filling the whole interior of the seed, doubled 

 upon itself twice, pale yellow or in immature seeds deep green ; the 

 incumbent cotyledons conduplicate, that is folded upon themselves 



