Term:

Aril half I-beam
Definition:

An aril that runs the length of the side of the seed and then abruptly turns to cover one or both ends of the seed.
Notes:

I-beam arils are limited to a clade currently retained in Eschweilera called the E. integrifolia clade by Huang et al. (in review). This clade is restricted to western Amazonia, the Andes region of Ecuador and Colombia, and into Panama. This type of aril possesses dense tissue and when dried is still well preserved in contrast to the poorly preserved lateral arils of the E. parvifolia clade. We hypothesize that some I-beam arils give rise to spreading arils.