Hill and Johnson, Eucalyptus (Myrtaceae) 
511 
very thinly peeling bark leaving a powdery salmon or orange fresh surface is uniform 
in the two groups, and may be a synapomorphy, as may also the disjunct, petiolate, 
rounded juvenile leaves. The thickened inner calyptra is apomorphic in series Albae, 
although not clearly present in all species of the series. The thickened valves are also 
apomorphic in this series. 
The most likely sister group to the red gums is section Transversaria, which shows 
similarities in seed coat structure, the proliferation of ovules on the placenta, and the 
subterminal hilum in some groups (although the latter is possibly a result of close 
packing caused by the increased number of rows of ovules). 
The first Red Gum to be described was E. tereticornis Sm. (1791). Bentham (1867) 
recognised two Red Gum species, which he included in Series Nomales subseries 
Subexserlae (together with members of Sections Transversaria, Bisectaria , Maidenaria and 
Adnataria sensu Pryor & Johnson, 1971). 
Maiden (Crit. Revis. Eucalyptus 1903-1933, 6) recognised five species, placed in section 
Macrantherae of his anther classification. These he then placed (with many other 
species) in subsection Tereticomes series Leiophloiae and Lepidophloiae, and subsection 
Longiores series Non-Corymbosae. 
Blakely (1934) recognised 10 species and four varieties (three of which are here treated 
as species), placing them in widely different groups (Table 3). 
Table 3. Placement of tropical red gum species by Blakely (1934) 
Species 
Section 
Subsection 
Series 
Subseries 
E. herbertiana 
Macrantherae 
Tereticomes 
Exsertae 
Phaeoxyla 
E. confluens 
Macrantherae 
Tereticomes 
Exsertae 
Erythroxyla 
E. brevifolia 
Macrantherae 
Tereticomes 
Subexsertae 
Argophloiae 
E. alba 
Macrantherae 
Tereticomes 
Subexsertae 
Argophloiae 
E. platyphylla 
Macrantherae 
Tereticomes 
Subexsertae 
Argophloiae 
E. bigalerita 
Macrantherae 
Tereticomes 
Subexsertae 
Argophloiae 
E. houseana 
Macrantherae 
Normales 
Argyrophyllae 
E. apodophylla 
Macrantherae 
Normales 
Argyrophyllae 
E. mooreana 
E. umbrawarrensis 
Macrantherae 
Micrantherae 
Normales 
Subulatae 
Argyrophyllae 
Blake (1953) recognised seven species, placing them (along with many other species) 
in four different series. 
Pryor and Johnson (1971) grouped the red gums in section Exsertaria, with three series. 
The first was series Albae, comprising eight published species and forshadowing three 
new species and reduction of three of Blakely's species to subspecies. This 
arrangement included all of the then known taxa except the problematical 
E. umbrawarrensis Maiden, but also included the taxon later published as E. urophylla 
S.T. Blake, now known to belong to Section Transversaria. All remaining red gums were 
placed in series Tereticomes, and the enigmatic E. michaeliana Blakely was placed in a 
third monotypic series in this section. 
Chippendale (1988) followed the series of Pryor and Johnson, with the recognition of 
all of Blakely's species and the inclusion of E. umbrawarrensis (following Johnson 1972), 
