He made important contributions to the botanical literature, including the publication of the comprehensive work Plantarum Vascularum Genera, and publications of monographs on the families Polygonaceae (especially the genus Polygonum), Lauraceae, Proteaceae, Thymelaeaceae and Hernandiaceae.
Dia membuat kontribusi penting untuk literatur botani, termasuk publikasi karya komprehensif Plantarum Vascularum Genera, dan publikasi monograf pada familia Polygonaceae (terutama genus Polygonum) , Lauraceae, Proteaceae, Thymelaeaceae dan Hernandiaceae.