mycorrhiza
noun
my·cor·rhi·za ˌmī-kə-ˈrī-zə 
plural mycorrhizae ˌmī-kə-ˈrī-ˌzē also mycorrhizas
also mycorrhizas : the symbiotic association of the mycelium of a fungus with the roots of a seed plant
mycorrhizal
ˌmī-kə-ˈrī-zəl
adjective 
Example Sentences
Recent Examples on the Web And perhaps more important, as plants pull carbon from the air, their roots inject some of it into the soil, feeding microorganisms and fungi called mycorrhiza. 
Moises Velasquez-manoff, New York Times, 18 Apr. 2018 There are many relationships between plants, insects and soil organisms specific to each community; one very specific and important relationship to the community is mycorrhiza. Patrice Hanlon, The Mercury News, 25 Jan. 2017
Moises Velasquez-manoff, New York Times, 18 Apr. 2018 There are many relationships between plants, insects and soil organisms specific to each community; one very specific and important relationship to the community is mycorrhiza. Patrice Hanlon, The Mercury News, 25 Jan. 2017 Word History
Etymology
New Latin, from myc- + Greek rhiza root — more at root
First Known Use
1886, in the meaning defined above