POLYGOXACE^ 439 



First to third pairs oblate, emarginate or bifid, like the coty- 

 ledon of a Convolvulus or Brassica, giving off a few leading nerves 

 into the side lobes. 



Polygonum sphserostachyum, Meisn. 



Primary root normal. 



Hypocotyl very short and unapparent. 



Cotyledons entire, almost orbicular, about 4 mm. in diameter, 

 glabrous, trinerved, with long petioles from T5-2 cm., which 

 joining at the base of the leaf form a hollow tube through which 

 the real leaves pass, giving the appearance of an erect hypocotyl 

 with sessile cotyledons. 



Stem at first very short, so that the leaves appear radical. 



First leaves radical, obtusely lanceolate, alternate, simple, entire, 

 light green with long petioles from 2'5-3 cm. ; midrib with numer- 

 ous lateral veinlets. 



Fagopyrum esculentum, Moench. (fig. 619). 



Fruit an achene, acutely or obtusely trigonous or sub-three- 

 winged, crustaceous, brown, sometimes with black transverse stripes, 

 or entirely black, glabrous, much longer than the persistent withered 

 perianth, slightly narrowed to the base, but more to the apex. 



Seed large, ovoid-trigonous, filling the cavity of the ovary and 

 conforming to it in shape ; testa very pale brown or straw-coloured, 

 glabrous, shining ; hilum basal ; chalaza rather large, conspicuous, 

 orbicular, reddish-brown, basal ; micropyle apical. 



Endosperm copious, dry and floury, white. 



Embryo very large, lying in the centre of the endosperm and 

 variously stretched from one angle 

 of the seed to another, and equal 

 in length to the seed, straight ; 

 cotyledons very wide, variously 

 twisted about or plaited, often 

 striking into two out of the three 

 angles of the seed, and these follow- 

 ing the interior of the testa for FlG . m. 9 . Fagopyrum esculentum. 



Some distance, apparently Outside A > transverse section of seed, x 4. 

 . f B, embryo, x 8. 



the endosperm, very shortly petio- 



late ; radicle rather large, subfusiform, tapering to an obtuse point, 



completely hidden by the folds of the cotyledons. 



Seedling. 



Hypocotyl 6-12 cm. long, 1-5-2' 5 mm. thick, succulent, terete, 

 glabrous, red. 



