104 FLOWERS. 



(55) Lily of the Valley. 



The inflorescence of Convallaria mqjalis, Linn. (N.O. Lili- 

 aceac). 



The lily of the valley produces a graceful unilateral raceme 

 of fragrant flowers with white campanulate corollas, each of 

 which bears on its inner surface six stamens with large anthers. 

 The ovary is trilocular, and is crowned with a short, thick style. 



The inner epidermis (ei) of the perianth is composed of poly- 

 gonal cells with smooth cuticle, and is provided with stomata, 

 each of which is surrounded by four or five cells. 



The outer epidermis (ee) is striated, and consists of smaller 

 cells. The parenchymatous tissue between these two layers is 

 traversed by numerous fibre-vascular bundles, and contains 

 aggregations of acicular crystals in some of the cells, which are 

 distinguished from the neighbouring ones by their larger size. 



The thecse of the anthers are largely composed of spirally, 

 thickened cells (an). The stigmata are covered with a striated 

 cuticle, and provided with numerous papillae. 



The powder of this flower contains in addition numerous 

 debris derived from the peduncles, pistils, ovaries, etc., as well as 

 vessels derived from the veins, acicular crystals of calcium 

 oxalate and pollen grains. 



The diagnostic characters of powdered lily of the valley 

 flowers are : 



(a) Cells from the perianth with acicular crystals. 



(b) Striated surfaces of the stigmata and papilla. 



(c) The epidermis of the peduncle with elongated cells. 



(d) The cells of the perianth, with acicular crystals of 



calcium oxalate. 



