Complex sentence: Marquand wrote numerous papers on the flora of East Asia, notably on "Cyananthus", "Buddleja" and gentians, although his private interest was Bryophytes, which he studied in the Alps and the highlands of Great Britain during his vacations.
Split into simpler sentences: 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.