Figure 1: Typical Asteraceae seed unit

Seed Unit of Asteraceae

The typical seed unit of the Asteraceae (Compositae) is the achene, a one-seeded, indehiscent fruit. 

The pericarp is strongly developed and often resembles a seed coat in structure; the seed coat and endosperm are much reduced or absent.

Figure 1 shows sunflower seeds, typical Asteraceae seed units.