“Shiitake” (an edible mushroom native to East Asia) sounds like “shit-talkie,” and there are jokes.
   
“I’ve discovered a new species of fungi. It likes to gossip about others behind their backs. I call it the ‘shit-talking mushroom’” was posted on Twitter by Audell Beckham Jr. on August 8, 2013. “What do yo call a fungi that loves to gossip? A shit-talky mushroom” was posted on Twitter by Advil Linguine on March 26, 2016. “What kind of mushroom loves to gossip? A shit-talkey” was posted on Reddit—Puns on August 5, 2020. “What kind of mushrooms always gossip about you behind your back? Shit-talk-y mushrooms!” was posted on Reddit—Jokes on February 8, 2022.
     
       
Wikipedia: Shiitake
The shiitake (/ʃɪˈtɑːkeɪ, ˌʃiːɪ-, -ki/; Japanese: [ɕiꜜːtake] Lentinula edodes) is an edible mushroom native to East Asia, which is now cultivated and consumed around the globe. It is considered a medicinal mushroom in some forms of traditional medicine.
       
Twitter
Audell Beckham Jr.
@RealAudfuture
I’ve discovered a new species of fungi. It likes to gossip about others behind their backs. I call it the “shit-talking mushroom.”
5:32 PM · Aug 8, 2013·Twitter for iPhone
   
Twitter
Staggering Blows
@StaggeringBlows
@LawnGnomeChrome once referred to someone spreading slanderous gossip as a shit-talkin’ mushroom.
5:52 PM · Feb 16, 2014·Twitter for iPhone
   
Twitter
if you see this, no i dont forgive you
@nonbinarylich
what do you call a fungus w a gossip problem?
i shit talky mushroom
5:43 PM · Dec 2, 2015·Twitter for iPhone
   
Twitter
Kayla.
@yurgurl_mikayla
What do u call mushrooms that gossip? ....shit-talking mushrooms
5:42 PM · Jan 6, 2016·Twitter for Android
   
Twitter
Advil Linguine
@MushGoblin
What do yo call a fungi that loves to gossip? A shit-talky mushroom…
2:44 AM · Mar 26, 2016·Twitter for Android
   
Twitter
Molly
@molly_gerrald
What do you call a fungus that gossips a lot? Shit-talkie mushroom. Get it? Like shiitake mushroom
1:36 PM · Jul 28, 2017·Twitter for iPhone
   
Twitter
Dianna Cowern
@thephysicsgirl
What type of mushroom gossips the most?
The shit-talky.
7:06 PM · Aug 16, 2017·Twitter Web Client
 
Reddit—Jokes 
Posted by u/See_Related May 18, 2019
What do you call a mushroom that likes to gossip?
A shit-talkie
   
Twitter
cat
@foxandlynx
Replying to @bootybuttland
what do you call a mushroom that gossips? a shit-talkin mushroom
5:39 PM · Jul 19, 2020·Twitter for iPhone
 
Reddit—Puns
Posted by u/HandCrimped August 5, 2020
What kind of mushroom loves to gossip?
A shit-talkey
   
Twitter
ᴸᴵᴸmittins⁷
@mari__army01
WHAT KIND OF MUSHROOM LOVES TO GOSSIP?
A SHIT-TALKIE
5:01 PM · Feb 23, 2021·Twitter for Android
   
Twitter
kayla radin
@okay_rad
which mushrooms are the biggest gossips well it’s gotta be shit-talk-y mushrooms lol
9:52 PM · Feb 5, 2022·Twitter for iPhone
 
Reddit—Jokes
Posted by u/bennetthaselton February 8, 2022
What kind of mushrooms always gossip about you behind your back?
Shit-talk-y mushrooms!