GERANIACEyE 



315 



knob externally to the testa, which is slightly indented at this point, 

 thus apparently causing the emargination of the cotyledons. 



Endosperm none, or forming an extremely thin membranous 

 covering adhering to the inner surface of the testa. 



Embryo straight, large, filling the cavity of the seed and con- 

 forming to it in shape, pale yellowish-white ; cotyledons obovate- 

 oblong, minutely emarginate, subcordate at the base, plano-convex, 

 and rather fleshy ; radicle very short, subglobose, stout, obtuse, 

 much shorter than the cotyledons, which envelope half of it together 

 with the plumule, the other half protruding. 



Impatiens Balsamina, L. (fig. 234). 



Primary root a short tap-root, succulent, colourless, unbranched, 

 while many nearly horizontal rootlets spring from base of the hypo- 

 cotyl. 



Hypocotyl about 4 cm. long, 2 mm. 

 thick, terete, succulent, glabrous, red- 

 dish near the base, greenish-white 

 above. 



Cotyledons shortly stalked, not 

 quite equal, 2-2'5 cm. or more long, 

 about 1-5 cm. broad, broadly ovate, 

 cuneate at the base, apex rounded and 

 emarginate, otherwise entire, obscurely 

 palmatinerved with sunk midrib, con- 

 vex, quite glabrous, light green above, 

 paler below, somewhat succulent, not 

 very persistent. 



Stem erect, herbaceous, annual, 

 stout, succulent, terete, densely 

 pubescent, pale greenish-yellow ; 1st 

 internode l - 5-2or 3 cm. long, 2*5 mm. 



,1 . , , _ , FIG. 234. Impatiens Balsamina. 



thick ; 2nd 2-3 mm. long. Ha jf nat size 



Leaves simple, cauline, opposite 



or subalternate, petiolate ; stipules obsolete ; lamina lanceolate- 

 elliptic, acute, acutely serrate, with small, subincurved, gland-tipped 

 serratures, pale green above and shining, paler beneath, glabrous ; 

 nerves ascending and incurved, mostly alternate ; petiole rather 

 broad and widening towards the leaf, flattened above, convex and 

 pubescent beneath, 2-3 mm. long ; pubescence often extending on 

 to the midrib of the leaf underneath. 



1st to 3rd pairs lanceolate-elliptic, subacuminate, acutely ser- 

 rate, cuneate or tapering at the base. 



