DICOTYLEDONS 



63 



in more northern regions, compared with the same 

 species in South Europe.^ 



WoOD-SORREL FAMILY {Oxalidacece)? WoOD- 

 SORREL {Oxalis Acetoseila, Fig. 16). This Httle 

 plant occurs in our woods, etc. It has a creeping 

 stem, knotted with thick- 

 ened bases of the leaf- 

 stalks, which contain 

 much starch as reserve- 

 food. It has trifoliate 

 leaves, and " sleeps " by- 

 dropping the three leaflets 

 vertically, at night, slight- 

 ly folding them, so that 

 the underside of their 

 midribs meet against the 

 petiole. It has two kinds 

 of flowers, perfect and 

 ** cleistogamous." ^ The pig. 16. Oxaiis Acetosdia ; Wood- 

 flowers have five free 



sepals; five free, white petals and ten stamens; five 

 having longer filaments than the other five (see 

 figure). The pistil has five carpels, the ovaries 

 being coherent, but the styles are free. 



1 The above facts are taken from a paper by Dr. T. Spencer 

 Cobbold in the Veterinarian^ 1880. 



2 Sometimes regarded as a tribe of the Geranium Family 

 {Geraniacece). 



3 Self-fertilizing in bud, by "concealed union," as the 

 word means.. 



