82 



ON SEEDLINGS 



Cotyledons rotund or oblong, short, emarginate, petiolate, tri- 

 nerved from the base and alternately penninerved upwards, glabrous, 

 light green ; lamina '5-1 cm. long, 5-7 mm. wide ; petiole rather 

 broad, grooved above, dilated at the base and clasping, 8-11 mm. 

 long. 



Stem herbaceous, perennial portion very short ; elongated when 

 about to flower. 



Leaves simple, radical and cauline, opposite (primary ones alter- 

 nate), exstipulate, petiolate, glabrous in seedling, thinly hairy in the 

 adult ; petioles grooved above, semiterete, dilated and sheathing at 

 the base. 



No. 1. Rotund, subcordate at the base, slightly angled, but not 

 cut, five-nerved at the base and suboppositely nerved upwards. 



No. 2. Rotund, obtuse, cordate and five-nerved at the base, den- 

 tate with the nerves ending directly in the teeth. 



Ultimate leaves ovate, or subtriangular in outline, pinnatisect, 

 often unequal-sided, thinly hairy ; seg- 

 ments alternate or sometimes opposite, 

 frequently unequal on opposite sides of 

 the midrib, lanceolate, obtuse, much 

 narrowed at the base, coarsely, obtusely 

 and irregularly serrate, three- to five- 

 nerved longitudinally from the base, 

 strongly reticulate with nerves sunk on 

 the upper surface and prominent beneath. 



Centranthus macrosiphon, Boiss. (fig. 

 445). 



Primary root stout, tapering, with 

 fibrous lateral rootlets. 



Hypocotyl mostly subterranean, pale 

 or colourless, glabrous, terete, passing in- 

 sensibly into the root. 



Cotyledons broadly ovate and trun- 

 cate, emarginate, or almost square, petio- 

 late, glabrous, one-nerved ; lamina 7'5 

 mm. long 7 mm. wide ; petiole convex on 

 the back, channelled above, about 6 mm. 

 long. 



Stem annual, developed when about to 

 flower. 



Leaves simple, radical and cauline, opposite, decussate, glabrous, 

 alternately or suboppositely incurvinerved, reticulate, deep green ; 



FIG. 445. 



Centranthus macrosiphon. 

 Nat. size. 



