Eucalyptus microtheca F. Muell., J. Proc. Linn. Soc., Bot. 3: 87 1858. (Syn: Eucalyptus raveretiana var. jerichoensis Domin);
Common name: Coolabah, Coolibah, Flooded-box 




Eucalyptus microtheca
Photographed from Delhi


I take your word for it since you are our own beloved taxonomist

but how is the leaves and flowers different from other white flowered eucalytpus.. say the one I just saw from your collection…e. tereticornis
Eucalyptus tereticornis from Delhi-GSDEC68

how can I  a lay person teach myself that the pictures are really that of eucalyptus tereticornis?

If you will please take some time and tell us about the eucalyptus trees that were shown here during these two weeks…  in simple english…  that we can follow and appreciate.. like you did for the melons …
would be great..

Nice photograph. The photograph uploaded seems to be Eucalyptus microtheca

Eucalyptus is a large genus with so many species often difficult to separate, but here are tips to separate them
E. citriodora are rather distinct from others in strongly scented (more like odomos) leaves when crushed, flower buds almost as long as broad, cap pinkish, hemispherical and cup like with sunkun disc.
E. camaldulensis has similar shaped flower buds but light brown and not pinkish cap which is distinctly pointed, fruit has 4-5 slightly raised teeth in the center.
E. microtheca has narrow leaves forming dense drooping canopy, buds very small usually less than 5 mm long, pointed at tip, fruits barely 3-4 mm long with 3-3 spreading teeth longer than base.
E. tereticornis buds are longer, often up to 1.5 cm long, cap much longer than base and gradually tapered, fruit with 4-5 teeth, projecting upwards almost as long as base.
E. globulus has usually single large flower, fruit more than 20 mm across
E. Polyanthemos is very distinct in its almost rounded leaves, flowers in panicles and hemispherical cap
E. leucoxylon with usually 3-flowered clusters, on up to 12 mm long peduncles, conical cap, as long as base, fruit 10-12 mm across.
I hope that helps.

Thank you … but the eucalyptus trees don’t a flower more than a few weeks a years

so how does one id a tree with only the tree bark, and leaves… is more difficult

that was my original intent … because when traveling we only get  a day or hour long window of opportunity to photograph a tree…

I understand …, bark and leaves do help in ID, supplementing floral identification. Dense drooping canopy with narrow leaves is often distinctive for E. microtheca.