CUPULIFEILE 



539 



effect of pushing the primary one right across the middle of the 

 seed, and this position is retained permanently. 



Fruit a one-celled, one-seeded nut, of which there are two to four, 

 usually two, in an involucre, indehiscent, triquetrous, keeled from 

 the top to below the middle., tipped with the hairy five- to six-lobed 

 perianth and plumy remains of style, deep brown, shining, crusta- 

 ceous, glabrous except at the top which is pubescent ; by the early 

 rupture of the septa the ovary becomes one-celled, while the axile 

 placenta grows with it and equals it in length or nearly so. (Of. 

 Quercus.) 



Seed strongly trigonous, or subtriquetrous conforming to the 

 interior of the pericarp ; testa thin, membranous, pale brown, marked 

 with nerves proceeding from the chalaza to the micropyle, pendulous 

 from the top of the cell, or rather from the placenta near the top ; 

 chalaza basal, distinctly elevated ; hilum subapical or about 1 mm. 

 below the apex, small ; raphe long, running from the hilum along 

 one face, or along one angle of the seed in a wavy manner. 



Endosperm absent. 



Embryo straight, large, entirely filling the seed when mature, 

 and conforming to it in shape, colourless or pale yellow ; cotyledons 

 applied face to face, and plaited longitudinally, first with one large fold 

 reaching from one angle of the cell to the middle of the flat face oppo- 

 site, or in other words dividing the triangle in two equal halves ; both 

 cotyledons are then reversed on either side of the four folds form- 

 ing the first division, and after 

 proceeding backwards for some 

 way are again turned forwards in 

 the original direction, thus filling 

 the other two angles of the seed. 



Seedling (fig. 671). 



Primary root long, stout, 

 tapering downwards and after a 

 time giving off freely short fibrous 

 lateral rootlets. 



Hypocotyl erect, stout, be- 

 coming more slender upwards, 

 angled and furrowed, pale green, 

 soon becoming brown, glabrous, 

 3-5'5 cm. long. 



Cotyledons large, foliaceous, transversely oval, sessile, auricled 

 at the base, with a fan-shaped venation, the nerves radiating and 

 branching towards the margin from two main trunks, right and 



FIG. 671. Fagus sylvatica. 

 Half nat. size. 



