It is an Asteraceae, C. sinensis have a real flower, this is an inflorescence their fruits are also different, this will give achenes. the indentation of the margins of leaves are usually less pronunciate in C. sinensis and the colour is more glossy.
This plant is most definitely not Camellia sinensis,which is a tree grown as a shrub but an Asteraceae. Check to see if the seeds resemble those of Bidens sp.
The plant seems not to be Camellia sinensis. Apart from the useful opinions shown here, in addition, you may search and consult a botanic garden for its identification.