If you are asking how to extract a chemical pH indicator from some plant type, I don't know. If you want to know a plant that indicates the relative pH of the soil it grows in, Hydrangea. Its flower's coloration is exactly like litmus paper's reaction to acids and alkalis.
universal indicator
A pH indicator paper can be used to tell if a solution is acidic or basic and the rough pH range can be known
An example of an indicator would be Phenol Red, or Universal Indicator. Depending on the pH range of the indicator and the pH range of the substrates you would use the appropriate indicator.
Universal pH paper is a type of paper used to find the pH level of a solution and is an indicator.
Universal Indicator is used to test for the acidity of a solution, because the universal indicator has a wider range of pH that it can explain why a substance is acidic or basic.
You can make a simple pH indicator at home using red cabbage. There are a few other plants that will change colours in different pH levels.
The indicator is bromothymol blue.
universal indicator
A pH indicator is used only to measure the pH of the solution.
pH range of indicator should be in the rapid pH gradient.
Phenolphthalein is used as an indicator because the color of the solution is changed according to pH.
indicator
lithmus
A pH indicator paper can be used to tell if a solution is acidic or basic and the rough pH range can be known
An example of an indicator would be Phenol Red, or Universal Indicator. Depending on the pH range of the indicator and the pH range of the substrates you would use the appropriate indicator.
You can make a PH indicator solution out of blueberry juice, or you can buy litmus paper or use an indicator solution that you can buy at the store.
Indicators are substances sensitive to different ranges of pH.