138 ON SEEDLINGS 



Another modification occurs in Orychophragmus, which 

 has an oblong, subtriquetrous seed. A third and more re- 

 markable type is presented by Euzomodendron, Savignya, 

 Moricandia and Henophyton, the seeds of which are com- 

 pressed, the testa forming a line round the margin, or a 

 narrow or even broad whig similar to what occurs in Cheir- 

 anthus, Matthiola, Lunaria, or Vesicaria with accumbent 

 cotyledons. 



Transversely biplicate cotyledons occur in a few genera, 

 of which the principal is Heliophila, containing about fifty or 

 sixty species of annual or perennial herbs with a few shrubs. 

 The fruits vary considerably in being oblong, oval, linear- 

 lanceolate or linear and moniliform, and on this account the 

 genus has been split up into some half-a-dozen by different 

 authors. The seeds also vary in being oblong, oval, or almost 

 perfectly orbicular, much compressed or quite flattened laterally , 

 and wingless as in Heliophila pilosa, var. incisa (fig. 166), or 

 broadly winged in H. crithmifolia, H. callosa, and others. 

 There is a more or less deep notch at the hilum in winged 

 seeds. The cotyledons are incumbent, transversely biplicate, 

 and placed in the narrow plane of the seeds with their backs to 

 the placenta. They are consequently very narrow, their width 

 being dependent on the width or size of the seed and the 

 mutual pressure of the folds on the edges of one another. 

 Their thickness depends upon the thickness of the seed, as they 

 are adpressed face to face with their edges to the flattened 

 sides of the latter. Heliophila belongs to the tribe Sisyrnbriese. 

 Chamira, belonging to the same group, agrees with Heliophila 

 in its seeds and embryo. Palmstruckia and Cycloptychis 

 amongst the Isatidese have also transversely biplicate coty- 

 ledons, and Carponema, classed under the Eaphanese, is re- 

 markable in having oblong, terete seeds and cotyledons like 

 those of Heliophila, to which it is closely allied. See Sond. 

 'Kevis. Helioph.' 3, t. xvii. Senebiera may be included in 

 this group. 



Spirally convolute cotyledons occur in the four known 

 species of Bunias. The fruit is short, ovoid, tetragonous, 

 lignified, one- to two-celled with a somewhat compressed seed 

 in each cell, the appearance being due to the shrinking of the 



