where did its name originate from?
Greek words ὑγρός ("hygros") and μέτρον ("metron").
Astraeus hygrometricus
The specific name is derived from the Greek words ὑγρός ("hygros") "wet" and μέτρον ("metron") "measure". 
what is astraeus hygrometricus? A species of fungus where is it found? Temperate and tropical regions; Africa, Asia, Australia, etc.
wiki:24690652
Astraeus hygrometricus [SEP] Taxonomy, naming, and phylogeny
The resemblance to "Geastrum" species (also known as true earthstars) accounts for the common name "false earthstar". The specific name is derived from the Greek words ὑγρός ("hygros") "wet" and μέτρον ("metron") "measure". The German Mycological Society selected the species as their "Mushroom of the Year" in 2005. Studies in the 2000s showed that several species from Asian collection sites labelled under the specific epithet "hygrometricus" were actually considerably variable in a number of macroscopic and microscopic characteristics. Molecular studies of the DNA sequences of the ITS region of the ribosomal DNA from a number of "Astraeus" specimens from around the world have helped to clarify phylogenetic relationships within the genus.