(photos taken ingame)

Orange Shrooms are for Flame Stalkers and can be mainly found in Ravine.
Blue Shrooms are for Shadow Scales and can be found in several different locations.
Yellow Shrooms are for Acid Spitter Drakes and can be found in different locations.

Green Shrooms can heal you and will frequently spawn in some places where elder shrooms spawn.
Toxic Shrooms are a good food source for Shadow Scales, Acid Spitters and young Flame Stalkers.

Island Shrooms will spawn every 1 hour, no sooner or later.
Spawns can give a green, yellow or blue elder Shroom.

133N 121E -- Yellow
140N 118E -- Blue
122N 117E -- Any

Cave will spawn a shroom every 1 hour. No sooner or later.

410S 40W -- Yellow

Ramp will spawn a shroom every 1 hour. No sooner or later.

156N 458E -- Blue

Shrooms spawn times can be random here.
Mountain Lake / Paradise, is a 50/50 zone , spawns can give a green, yellow or blue elder Shroom.

179N 148W

Swamp has 3 spots next to each other which can spawn at random times.
Spawns can give a yellow, blue , or green elder shroom

331N 528W

Crater has 3 spawn points beside each other which will spawn shrooms at random times.
Crater, is a 50/50 zone , spawns can give a green, yellow or blue elder Shroom.

320S 567E

Shroom spawn times will be random.
Elder forest is a 50/50 zone , spawns can give a green, yellow or blue elder Shroom.

Side note: In Elder Forest
Food: 400S 360W
Water: 485S 630W

Shrooms
6S 688W
170S 723W
296S 732W
385S 740W
500S 714W
595S 753W
638S 658W
308S 637W
544S 552W
457S 553W
240S 562W
200S 472W
318S 471W
358S 456W

Most shrooms have a timer between 1 hour to 2 hours.
Wall shroom can spawn between 30 minutes to 1 hour.
Ravine will have a 50/50 Green or orange Shroom spawn, all but the wall spawner.

331S 477E
404S 388E
409S 385E
410S 392E
420S 387E
432S 372E
424S 374E
438S 380E
437S 367E
445S 377E
442S 366E
486S 307E
480S 297E
481S 290E
522S 238E
546S 229E
577S 161E
586S 149E

This is all locations in game but if you have any other info feel free to comment. Thank you,