378 SYSTEMATIC BOTANY 



there is a ring of tissue at the junction of these two,, 

 it represents the perianth. 



There remain to be explained only the hairy fila- 

 ments which are intermixed with the stalked anthers. 

 In young stages while the parts are still stiff enough 

 to be readily distinguished, it may be seen that for 

 the most part they go with the stalked anthers, one 

 to each, so that they must be the bracteoles of the 

 flowers; but some are sterile stalked-stamens, i.e. 

 sterile flowers. The green involucre which surrounds 

 the cyathium is made up, like that of the capitulum 

 of the COMPOSITE, of bracts. 



The zig-zag arrangement of the staminate flowers 

 shows that they are arranged in the same way as in 

 HELIOTROPIUM, i.e. in the form of a scorpioid cyme 

 whose axis is very short and curves back from the- 

 centre of the cyathium towards the periphery, while 

 the pedicels of the individual flowers are in proportion 

 longer than with HELIOTROPIUM. 



The cyathium then is a condensed inflorescence, very 

 much more condensed than even the capitulum of the 

 COMPOSITE. The latter may be regarded as simply 

 a condensed umbel, in which there are no pedicels,, 

 or as a spike in which the peduncle is expanded lat- 

 erally instead of upwards. But in EUPHORBIA and 

 POINSETTIA there are; enclosed in the involucre, five 

 distinct scorpioid cymes of staminate flowers, sur- 

 rounding a single ovary flower, or, in all five or six 

 separate inflorescences of very much reduced flowers. 



Though this family is named after the genus EU- 

 PHORBIA, by far the greater have the simple flowers 

 of RICINUS, CODI^UM and ACALYPHIA. EUPHORBIA 



