GRUCIFEIIJE. 



185 



outer face of one of the cotyledons, not on their commissure ; they 



sisymbrium are straight, convolute or more or less folded on them- 



(Gar'iic- selves transversely, but not longitudinally. Only excep- 



mustard). tionally are they accumbent ; and by this character, slight 



though its importance be, we distinguish the series 



Sisymbrinea, containing twenty-one genera : Sisymbrium, 



Conringia, Erysimum, Porphyrocodon, Smeloioskia, Zerdana, 



Christolea, Greyyia, Syrenia, Pac/iypodium, Stanleya, Warea, 



Streptoloma, Dontostemon, Lepidostemon, Malcolmia, Hesperis, 



Tetracme, Schizopetalon (fig. 216), Helinphila (fig. 217, 218), 



and Chandra. These genera are distinguished from each 



other mainly by the following traits : the siliqua has rarely 



horns towards its apex {Tetracme), and 



may be sessile or stipitate ; SchizopetahnWaikeri- 

 the style is simple, capitate ^\^\<\ J ^ 

 or divided into two short 

 lobes, or two longer lobes, 

 free erect, or connate and 

 coalescing into a single co- 

 nical body. The cotyledons 

 may be folded once, or more 

 rarely twice, on themselves; 

 the stamens are free, exappendiculate, or else the longer ones have a 

 basal appendage or tooth ; finally 

 the petals, usually entire, are 

 pinnatifid in the one genus 

 Schizopetcdum . 



With the same general organi- 

 zation in flowers and fruit, the 

 Cabbages 1 (Fr., Choux ; 219-241) 

 have been made the type of a 

 third subseries Brassicinece, only 

 because their seeds differ in the 

 folding of the cotyledons on them- 

 selves and the radicle. Their 



Fig. 214 



Fruit. 



Fig. 215. 

 Transverse sect. (&). 



Fig. 216. 

 Flower. 



Ileliophilia variabilis. 



Fig. 217. 



Fig. 218. 



flowers, nearly the Same aS tllOSe Flower, perianth removed(i). Long. sect, of flower. 



1 Brassica T., Inst., 219, t. 106.— L., Gen., S>/st. Teg., ii. 582; Prodr., i. 213 (part.).— 

 820.— Adans., Fam. des PI., ii. 417.— DC, Spach, Suit, a Buffon, vi. 356.— Enul., Gen., 



