10 SPRING FLOWERS. 



be found the dwarf and unpretentious Wood Sorrel^^ a lovely 

 little wilding, representing the family of Oxalidaceous plants. 

 This has peculiar knotty fleshy sterns^ and trifoliate leaves 

 like those of the clover. It has also polypetalous (here five- 

 petaled) regular flowers, in which both calyx and corolla will 

 be found, the calyx consisting of five green sepals, the corolla 

 of five equal obovate white petals ; within these are ten sta- 

 mens, half of which are as long again as the others, and five 

 separate styles surmounting the ovary. This elegant little 

 plant is maintained by some antiquaries to be that which fur- 

 nished St. Patrick with his illustration of the doctrine of the 

 Trinity, though others contend for the Trefoil or Clover, which 

 is now more commonly adopted as the Irish Shamrock. 



The foregoing plants (excepting the Primrose, the Snow- 

 drop, and the Crocus) all belong to a primary division of the 

 Dicotyledons or Exogens, called Thalamiflores, and they 



have these distinguishing marks in common : 



{a) The petals are distinct from the calyx, and from each 



other : very seldom absent. 

 (b) The stamens are hypogynous, that is, they have their 



point of attachment below the ovary, which latter 



is the young seed-vessel. 



We have next to consider one or two examples of another 

 great subdivision of the Dicotyledons, called Calyciflores, 

 which has these peculiarities : — 

 (a) The petals are usually distinct. 



{b) The stamens are perigynous, that is, appearing to grow on 

 one of the organs surrounding the ovary, either calyx 

 or corolla ; or epigynous, that is, apparently growing 

 from the summit of the ovary itself. 



* Oxalis Acetoaella — Plate 2 C. 



