Too be safe I acclimate all plants aquatic and terrestrial plants.
It's generally not a good idea to transfer exterior or wild pond plants to indoor aquariums, as they can transfer potentially harmful micro organisms to your system. I once successfully acclimated wild Horn Wort from my parents pond. After slowly matching temperatures in the summer and adding water from tanks into the pond water and plants, (separate container) then after what I thought was a thorough cleaning and rinsing with some aquarium water. ( I discarded the rinse and pond water. The Horn Wort was doing well, but after a few days I noticed all manner of visible micro organisms and small aquatic insects. While my fish delighted in chasing down and devouring the pond organisms, I was alarmed that I might introduced some harmful biological medium to my water systems. I was fortunate I had otherwise good water quality and healthy fish. I Freshened up my activated charcoal, increased my Prime dosage with frequent water changes and quickly got rid of the unwanted vistors also with the fishes' help. I suffered no fish deaths or illness', except I noticed some of my smaller fish, neon and white clouds acting peculiarly. They were acting frantic and fleeing, and clustering at one end of the tank, at times and acting like they were being netted.
After several weeks I barely caught sight of a quick, dark and elusive shadowy shape in the farther recesses of one aquarium. I tried to find it soon after but couldn't find whatever it was.
One day I took out the filter catridge for a gentle scrub and rinse with tank water. At the bottom or the filter chamber, INSIDE, was a good sized; 2 inch, wicked looking armored nightmare insect which I took to be a dragonfly nymph. Further research determined it be a gadfly nymph if I recall correctly. It has been a few years. I removed to a çontainer and took it to friends house, and released it in an old junk barrel in his back yard. The barrel had standing rainwater and mosquito larvae in it.
After that I kept a close eye on the tank. And my neons and clouds still weren't acting normally. Some time later I saw a larger, bulb Eyed later staged nymph actually chasing my fish. This one was difficult to capture and extricate from my net. I went to town searching ever crevice in my several tanks. I found a third medium sized nymph behind the in tank filter. I found a final one when I was lifting and moving some a broad leaf Ludvigia It was clinging to the bottom side of a leaf. I assume that is how they accidentally migrated into my tank in a smaller incarnation.
I was haunted for quite sometime after, constantly checking my plants and hidden corners. That was the last one though. Ever after I do not procure any plant samples from my parents' pond, no matter how much I'm tempted. Not worth the nightmare. I just spend a few dollars and get a domestic version or resemblence of whatever plant strikes my fancy from the ponds' many aquatic flora. The other pond inhabitants include; wild ducks, geese, big bullfrogs, bass and an occasional crane. Also there are uncountable insects and microbes. Over time the several good size ponds have naturalized.
The Horn Wort should perhaps only be counted as a partial success. For all the trouble, I was happy to see the Horn Wort flourish and transform and expand into a graceful, lacy, bushy version of the wild parent plant. It lasted for 2 years, and turned into as Colin_T said - "mush". but sickly whiteish, not viable green. Not anemic. Or lacking fertile fish water. As compared, my domestic aquatic plants have flourished for years and send out descendants, with and without my help. Lesson learned, I probably won't be doing that again.
