noun, plural hy·po·thal·li [hahy-puh-thal-ahy, hip-uh-] /ˌhaɪ pəˈθæl aɪ, ˌhɪp ə-/.
Examples from the Web for hypothallus
Plasmodiocarp very much flattened, longitudinally creeping and reticulate or altogether widely effused; hypothallus none.The Myxomycetes of the Miami Valley, Ohio|A. P. Morgan
In the centre of the fructification, next the hypothallus, the sporangia are very imperfectly differentiated.
The hypothallus is quite distinct, extra-marginal, and in substance like to the peridial wall.
The hypothallus is sometimes noticeable under some of the sporangia where closely crowded, but is not a constant feature.