Educated at Elizabeth College, Guernsey, from 1906 to 1910, he attended Lycée Henri-IV in Paris for a year before entering Bedford School (1911-1913).
[1] On leaving Cambridge in 1919, Marquand was appointed research assistant, investigating Avena at the new Welsh Plant Breeding Station at Aberystwyth.
Marquand wrote numerous papers on the flora of East Asia, notably on Cyananthus, Buddleja and gentians.
His private interest was Bryophytes, which he studied in the Alps and the highlands of Great Britain during his vacations.
Marquand drowned there on 1 July 1943, while on a boating expedition in search of rare algae.