CRUCIFER^E 



159 



Cotyledons and radicle arranged as in H. pilosa. 



Primary root annual, tapering, but little branched. 



Hypocotyl erect, terete, pubescent, 2-2*5 cm. long. 



Cotyledons linear, acute, subterete, distinctly channelled along 

 the whole upper surface, very thinly pilose or pubescent, sessile, 

 slightly narrowed to the base, 2-3-8 cm. long, deciduous, becoming 

 disarticulated from the stem. 



Stem annual, erect, terete, pubescent ; 

 1st internode 9-10 mm. long. 



Leaves simple, cauline, alternate (1st 

 pair almost opposite), exstipulate, petiolate, 

 thinly pubescent, finely divided or cut, with 

 linear subterete acute segments, all chan- 

 nelled on the upper surface ; petiole semi- 

 terete, channelled above, articulated with 

 the stem. 



Nos. 1 and 2. Almost opposite, pinnati- 

 sect, with one or two alternate segments on 

 each side. 



Succeeding leaves with more numerous, 

 opposite or alternate segments. 



Plant running to seed very rapidly, even 

 in the seedling pots before being planted out. 



Heliophila amplexicaulis, L. (fig. 167). 



Primary root long, tapering downwards, 

 with short lateral rootlets. 



Hypocotyl glabrous, purple, dotted with 

 green, 8-10 mm. long. 



Cotyledons linear obtuse, entire, tapering 

 insensibly into the petiole, glabrous, erect 

 or ascending, green or more or less tinged 

 with purple ; a midrib is present, but no 

 other venation is discernible ; 2-2- 5 cm. 

 long, 1-1-5 mm. wide. 



Stem erect, terete, glabrous, green or 

 becoming purple and dotted with green, annual ; 1st internode 

 5-10 mm. long, 2nd 6-13 mm. 



Leaves opposite (at least on the lower part of the plant up to 

 and including the fifth pair), sessile, with numerous, alternate, ascen- 

 ding, slender nerves, proceeding from the midrib at a very acute 

 angle, incurved, and uniting with one another at their apices, while a 

 number run close to the apex of the leaf, and curving inwards unite 



FIG. 167. Heliophila 

 amplexicaulis. Nat. size. 



