Fly due East across the Atlantic, you come across the ancient Egyptian kingdom of the Pharaohs (its huge spreading from Atlantic and beyond the Red Sea). When you have said your hellos to the belly dancers, take off again and fly due East and you come across the ancient Persian kingdom of Darius/Cyrus(its huge from Arabia to mid South Asia). Appreciate the beauties and good food. When finished take off again and fly due East and you come across the ancient kingdom of the Laos/Cambodia(its huge spreading from mid South Asia to Pacific). I don't know whose beauties are better but appreciate them. In the morning take off again and fly due East, you reach home.
What have they all got in common? Not the beauties but the SUN and the Pyramids. They all worshiped the sun god Raa. Why? The sun passes overhead. I have spent twenty years of my life in this sun belt and should exactly know about its aridity and heat. You are correct in writing the zone invented by you, there is no zone talking about this extra special belt either.
Conclusion. This Zone scheme does not cater to all conditions but the incorrigible amongst us wont give up trying to grow plants from this area. I also love to dabble for the challenge in these Equatorial area plants. Jonna, cannot blame people who have not appreciated prickly heat one inch in diameter, now can we?
Regards,
Arif.