Etaerio

Sometimes the achenia are aggregated upon a common receptacle, forming what is called an etaerio, as in the ranunculus, in which they are placed upon a dry receptacle, or in the strawberry, in which the receptacle is fleshy.

Source: wiktionary

1953, John Melvin Lowson, Textbook of Botany, University Tutorial Press, page 318, Clematis: actinomorphic; 4 petaloid sepals; petals 0; fruit an etaerio of achenes with persistent hairy styles.

Source: wiktionary

Four types of aggregate fruits include etaerios of achenes, follicles, drupelets, and berries. Ranunculaceae species, including Clematis and Ranunculus have an etaerio of achenes, Calotropis has an etaerio of follicles, and Rubus species like raspberry, have an etaerio of drupelets. Annona have an etaerio of berries.

Source: wiktionary