As stated in the previous posts, the appearance of these types of mushrooms on a black locust is indicative of heartwood rot. And heartwood rot is incurable. The tree is dying but may take a number of years before it fails completely. The immediate concern is that trees with heartwood rot are structurally unstable and prone to wind breakage and dropping limbs. I'd consider removal if sited where it could fall on the house, cars or passersby.

ahhh..more pot facts .... where are you ???? you said: I plan on keeping them inside for a couple of months while they get a head start on growing and was wondering what exactly should I do to help them stay healthy? ==>>> well thats easy.. PLANT THEM OUTSIDE ... or leave them outside in pots properly stored for winter .... interfering with the plants NATURAL annual Circadian rhythm .. will NOT give them a head start ... and i would suggest.. that if you dont kill them.. you will stunt them .... besides the natural dormancy period.. short of a properly controlled green house ... it will be near impossible to manage watering [media selection] .. heat.. and light .. in winter.. especially in a house that has a forced air furnace... humidity being the big problem with such ... and you cant just throw them outdoors in winter in many places .. again.. where are you ... now all that said... i am not trying to stop you from experimenting... that is ALWAYS good.... but you will need to address every variable i mentioned .. and probably a few others .... and come near to perfecting them ... to succeed ... your thoughts of giving them a head start by keeping them close and cosy ... borders on what i call ... LOVING YOUR PLANTS TO DEATH .... the bottom line.. is that deciduous trees NEED to go dormant .... and you cant change that .... no matter how much you 'care' .....ma nature has been at this for billions of years.... and you arent going to out think her ... but again... do have fun trying... ken Here is a link that might be useful: link

I'm with Maackia...agree that invasive issue is overplayed in eastern NA. It is a very successful early successional forest species that fixes soil nitrogen and when it reaches high densities, there are native insects that effectively target Robinia, allowing later succession forest species to take hold. It is shade intolerant so mono-culture stands of Robinia are rarely self sustaining (unless the disturbance that facilitated its establishment continue). Its invasive label in eastern NA partly stems from its spread into meadows and fields that previously experienced regular low intensity fires and for its toxicity to domestic livestock. Its characteristics (except for the N2 fixing) are similar to Eastern Red Cedar...a highly successful early succession forest species that has benefited from anthropogenic landscape disturbances and from fire suppression policies.

I can definitely see the honeylocust I.D. based on that one branch/twig laying on the trailer bed. Do you have that branch or has it already gone up in smoke? A close up picture of the buds would confirm.