what does universal veil mean?

UNIVERSAL VEIL as NOUN

Meaning
- membrane initially completely investing the young sporophore of various mushrooms that is ruptured by growth
- represented in the mature mushroom by a volva around lower part of stem and scales on upper surface of the cap
Synonym(s)
- velum (what does velum mean?)
Hypernyms(s) universal veil is a kind of… Example: animal is a hypernym of mammal, plant is a hypernym of flower
- plant part (what does plant part mean?)
- plant structure (what does plant structure mean?)