Above Pic : Ixora
Reference: Meenakshi Mukerji's Ornamental Origami
No of units: 6
Paper size used : 5" x 5" (can also use 3" - 5" square papers)
Difficulty: easy for beginners , easy to assemble and fairly sturdy model.
Paper used: normal color printer paper
Time: 1.5 to 2 hours
No glue used. No paper clips used while assembling.