Rhododendron macgregoriae F.Muell.

Shrub or rarely small tree. Leaves mostly in whorls of 3-5 at branch tips, mostly 5-10 cm long (occasionally more), 2-5 cm wide. Flowers 8-15 per cluster, tubular to 3 cm long, pale yellow to dark orange, or yellow in the tube and reddish orange at the lobes.

New Guinea

Forms natural hybrids.

Source: Davidson, B.; Craven, L.; Malone, B.; Davidson, R.; Wilson, J, ; Spencer, R. (1997). Rhododendron. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Asteranae
order      Ericales
family       Ericaceae
genus        Rhododendron L.