96 FLOWERS. 



(51) Cloves. 



The dried flower-buds of Eugenia caryophyllata, Thunb. 

 (N.O. Myrtacese). 



Each clove consists of a somewhat quadrangular stem-like 

 portion slightly contracted at the base ; this part is sometimes 

 interpreted as a calyx-tube, sometimes as the solid lower part of 

 the ovary. It is crowned by four thick, divergent, suboval 

 calyx-teeth in the centre of which there is a small rounded body 

 consisting of four imbricated petals enclosing the dried stamens 

 and style. 



The transverse section of the lower part of the stem-like 

 portion exhibits the following characters : The epidermis is 

 composed of polygonal cells covered with a rather thick cuticle, 

 and provided with stomafca. Below the epidermis is parenchy- 

 matous tissue well differentiated into three layers, viz., an outer 

 one with radially elongated cells, and numerous internal oil- 

 glands, a middle, collenchymatous layer traversed by 

 numerous fibro-vascular bundles in which thick sclerenchy- 

 matous fibres are conspicuous elements, and an inner, lacunous 

 layer. In the centre there is a moderately large nbro-vascular 

 bundle. 



Both the teeth of the calyx and of the petals consist chiefly of 

 parenchymatous tissue in which there are numerous oil-glands. 



The anthers are composed of small cells with pitted walls, and 

 larger cells with spiral thickenings. 



The powder also contains numerous pollen grains as well as 

 pericyclic fibres derived from the bundles in the lower 

 part of the clove. 



Powdered cloves possess no well-marked diagnostic characters ; 

 the following features may, however, be mentioned : 



(a) Epidermis of lower part of ovary, with thick cuticle. 



(b) Epidermis of calyx-teeth and corolla. 



(c) Fragments of the oil-glands. 



(d) Parenchyma of the corolla with numerous rosettes of 



calcium oxalate. Powdered cloves should not con- 

 tain sclerenchymafous cells (clove stalks) or starch 

 (mother-cloves). 



