1) Coming together 2) Growing together, fusing 3) Merging 4) Merging into a single group 1) Unitive 
plant parts fused or grown together to form a single unit.
• (a.) Growing together; cohering, as in the organic cohesion of similar parts; uniting.
Co`a·les'cent adjective [ Latin coalescens , present participle] Growing together; cohering, as in the organic cohesion of similar parts; uniting. 
coalescent 1. To grow together; to fuse. 2 To come together so as to form one whole; to unite.
coalescing adjective growing together, fusing; `coalescent tradititions`; `coalescent bones`