To distinguish the tenderness and maturity of the pumpkin on the vine, you can refer to the following three characteristics:

1. Branches: Observe the branches of the pumpkin. Thicker and emerald-green branches indicate that the pumpkin is nutritious and relatively fresh. If the branches have dried up or turned yellow, it means that the pumpkin has been harvested for too long or is already mature.

2. Size: Choose pumpkins with complete shape and moderate size. Usually, about 300 to 500 grams per melon is most suitable. Puguas that are too large or too small may not grow well, or they may take too long to harvest, and their quality may be affected.

3. Epidermis: Observe the epidermis of the pumpkin. Pu melons with downy and shiny skins indicate that they were harvested not long ago and taste tender. If there is no fuzz on the skin, or there are uneven marks on the surface, the pumpkin may be of poor quality.

The above methods are for reference only. The actual taste and quality may need to be evaluated based on specific varieties and cooking methods.