Aril spreading
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Title
Aril spreading
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Definition
The aril spreads around the entire seed and, thus, looks like a sarcrotesta. In contrast to a sarcotesta, a spreading aril arises from the I-beam aril and not the seed surface.
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Notes
Spreading arils are only found in the relatively small Eschweilera integrifolia clade. The larger E. parvifolia clade has lateral arils. We now believe that spreading arils are associated with I-beam arils. Cornejo 8057 was collected from the same tree of E. integrifolia but at different times of the year, September in 2008 and January 2012. In the 2008 collection the spreading aril was removed to reveal an I-beam aril., and when he removed the spreading aril the I-beam aril was removed with it. The 2012 collection shows an elevated ridge under the spreading aril. In some cases, species in that same clade seem to only have I-beam arils, e.g., Eschweilera jacquelyniae. In summary, there are spreading arils in some species with an underlying I-beam aril (e.g., E. integrifolia), I-beam arils that have some of their tissue spread over the seed (e.g., E. antioquensis), and other species that may just have an I-beam aril (e.g., E. jacquelyniae). All three of these types are found in the E. integrifolia clade. When collections of this clade are made and the seeds are mature, the spreading aril should be carefully removed to see if there is an I-beam aril present.
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Related Terms
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