How to distinguish Java on z/OS from Java on Linux on z/OS?

Question

Is Java on z/OS and Java on Linux on IBM Z systems distinguishable from each other by os.name and/or os.arch properties? What about UNIX services for z/OS, does it have distinctive Java distribution?

Update 1

My understanding is that z/OS uses dot or colon (?) as path component separator while Unix-like subsystem uses solidus. My expectation is that there is Java for z/OS which uses whatever native C library and executable file format z/OS has, using the dot/colon as separator, while z/OS UNIX subsystem and Linux on IBM Z use POSIX compatible C library and use ELF as executable format. I would expect there to be two different JREs, one for the z/OS Linux and another for the z/OS UNIX service subsystem. My expectation is that the EI_OSABI field in ELF file format header is distinct for Linux and for z/OS UNIX subsystem, thus there should be two different Java distributions.

Is there z/OS Java which runs outside any of the Unix-like subsystems?