Gauteng West Rand Black Eagle GeoArt Series

Welcom to the West Rand, Gauteng!
The West Rand geocaching community is very proud to present BLACK EAGLE GEOART, the only GeoArt series to date in South Africa depicting the rare Black Eagle!
Apart from the rich cultural history, the West Rand in Gauteng, South Africa is also home to an extremely active geocaching community. The West Rand geocachers are a social bunch and meet at least once every month to share stories, swap experiences and trackables and enjoy each other's company.
We hope you will enjoy exploring the beauty of the West Rand, Gauteng!
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This puzzle is dedicated to our 8 year old daughter.
Her motto is: “If there’s a tree, I have to climb it”.
https://www.earthtouchnews.com/natural-world/natural-world/top-10-iconic-african-trees/ lists the top 10 Iconic African Trees. Both the common name and the Botanical name of the first 4 are hidden in the grid. Find them, mark them and then use the REMAINING LETTERS to answer the following: If A=1, B=2, C=3.........
Use the 10th letter in line 3, 8th letter in line 12 and 6th letter in line 15 to find the combination.
The physical cache is not at the listed co-ords.
It’s at: S 26° 0.972' E 27° 42.39A'
BYOP
Just for fun; "Find the hidden phrase in the diagram and post it when you log your find. ;-)"