Linked from
The 12 pages that link to Corolla, each with the reason it gives.
RhododendronRelated: Rhododendron corollas vary in shape and color and help distinguish species.
CampanulaceaeRelated: Petal fusion and symmetry help distinguish major lineages within the family.
IpomoeaRelated: Fused, often funnel-shaped corollas are characteristic of many Ipomoea flowers.
PrimulaRelated: Primula’s five-lobed corollas are a conspicuous feature used in identification.
SyringaRelated: The fused, tubular corolla is a recognizable feature of Syringa flowers.