Decurrent

Adjective

1. Of plant parts: extending downward, most often in the case of leaf blades that partly wrap or have wings around the stem or petiole and extend down along the stem.
2. Of lamellae (the gills of a mushroom): broadly attached and extending down the stipe of the mushroom.

   "In this group of mushrooms, the attachment of the gills to the stipe is decurrent."

3. Running or extending downwards.