Origin of the Taxaceae aril: evolutionary implications of seed-cone teratologies in Pseudotaxus chienii

摘要

Fleshy structures that promote biotic dispersal by ingestion have evolved many times in seed plants. Within the yew family Taxaceae (six genera, including ), it remains controversial whether the characteristic fleshy structure surrounding the seed is interpreted as a novel outgrowth of the base of the ovule (i.e. an aril) or a fleshy seed coat that is entirely derived from the integument (i.e. a sarcotesta). This paper presents a detailed study of both wild-type and teratological seed cones of , including morphology, anatomy and ontogeny.