The =stem= is stuffed, later fistulose, even, fragile, striate often above the annulus.
"Studies of American Fungi. Mushrooms, Edible, Poisonous, etc." by George Francis Atkinson
Stem even, fibrous striate, outer bark subcartilaginous, flesh white, stuffed, becoming fistulose.
"The Mushroom, Edible and Otherwise" by M. E. Hard
The stem is thin and fistulose.
"Student's Hand-book of Mushrooms of America, Edible and Poisonous" by Thomas Taylor
P. more regular, convex, even, yellowish; g. almost adnate; s. fistulose.
"European Fungus Flora: Agaricaceae" by George Massee