You searched for: “cyathophorous
1. Cup-shaped.
2. An inflorescence (the flowering part of a plant, and especially the mode of its arrangement) with unisexual (either pistillate [female] or staminate [male]) flowers surrounded by a cup-like cluster of involucral bracts, e.g., a poinsettia.

Involucre refers to a circle or collection of bracts surrounding a flower cluster or head, or a single flower.