408 



ON SEEDLINGS 



a thickening of the chalaza, accumbent, lying in the broader plane of 

 the seed with their edges to the placenta ; radicle cylindrical-oblong, 

 obtuse, passing round the upper end of the seed and pointing down- 

 wards to the micropyle on the ventral aspect, much shorter than 

 the cotyledons. 



Seedling (fig. 267). 



Primary root tapering downwards, long, with a few lateral root- 

 lets. 



Hypocotyl erect, terete, very stout, slightly tapering upwards, 

 passing suddenly below into the primary root, glabrous, pale green 

 or stained with red, 1-3-2-5 cm, long. 



Cotyledons broadly oblong, obtuse, entire, slightly falcate and 

 shallowly indented on one side (by a thickening in the testa of the 

 seed), entire, slightly asymmetrical at the 

 base, on one side of which they are gradu- 

 ally tapered, and on the other truncate, 

 owing to the position of the radicle in the 

 seed, shortly petiolate, thick, fleshy, deep 

 green, opaque, and obscurely trinerved 

 at the base, glabrous ; lamina 1*4-1-5 cm. 

 long, 7'75-8'25 mm. wide ; petiole deeply 

 grooved above, convex on the back, about 

 5 mm. long. 



Stem erect, terete, silky, pale green or 

 somewhat hoary, ultimately woody ; 1st 

 internode 5-8 mm. long. 



Leaves compound, digitately trifoliolate, 

 cauline, alternate, stipulate, petiolate, silky 

 on the under side with adpressed hairs, 

 ciliate at the margin, glabrous above or 

 nearly so ; leaflets closely and alternately 

 penninerved, with the nerves branching 

 and uniting within the margin, forming 

 numerous reticulations; stipules small, 

 subulate, silky, at the very base of the 

 petiole. 



No. 1. Digitately trifoliolate ; lateral leaflets elliptic or ovate- 

 elliptic, often, if not always, unequal in size with a difference varying 

 from -5-4 mm. in length, acute or cuspidate, shortly petiolate ; 

 terminal leaflet lanceolate-elliptic, acute, longer and larger than 

 the lateral ones, shortly petiolate. 



Ultimate leaves digitately trifoliolate ; leaflets elliptic-lanceolate, 



FIG. 267. 



Laburnum vulgare. 

 Nat. size. 



