A biographic summary of the research of Dr Graham Charles George Argent (born 15 May 1941, died 24 April 2019) is presented, summarising his research career. Expedition information, including dates, collection number series and the names of collaborators, is given, as is a list of his publications, annotated with taxonomic decisions and the names of new species described within them.

Rhododendron loranthiflorum was previously regarded as an archipelagic endemic, with known stations in the Solomon Islands and New Britain. An exploratory survey of the Lakekamu Basin has now established the plant's presence on the southern side of the New Guinea mainland. The Lakekamu provenance represents a geographical disjunction distinguishable as a separate subspecies, and is formally described as subsp. lakekamuensis.

Chromosome counts for 27 species plus one intersubsectional hybrid are presented from all seven subsections of section Vireya in the genus Rhododendron. Twenty-three are new, and five confirm previously published counts. The plants originate from a wide geographical and altitudinal range; all have a uniform somatic number of 2n=26.