 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Hypogeal" – news ·newspapers ·books ·scholar ·JSTOR(March 2011) (Learn how and when to remove this message) |
Hypogeal,hypogean,hypogeic andhypogeous (lit. 'underground'; from Ancient Greek ὑπό (hupó) 'under' and γῆ (gê) 'earth')[1] arebiological terms describing anorganism's activity below thesoil surface.
Inbotany, aseed is described as showinghypogeal germination when thecotyledons of thegerminating seed remainnon-photosynthetic, inside the seed shell, and below ground.[2] The converse, where the cotyledons expand, throw off the seed shell and becomephotosynthetic above the ground, isepigeal germination.
Inwater purification works, thehypogeal (orSchmutzdecke) layer is a biological film just below the surface ofslow sand filters. It containsmicroorganisms that removebacteria and trap contaminant particles.
The termshypogean andhypogeic are used forfossorial (burrowing) andtroglobitic (orstygobitic)cave-living organisms. The opposite terms areepigean andepigeic.
The termhypogeous is used for fungi with underground fruiting bodies - for example,truffles. The opposite term isepigeous.