pertaining to the attachment of the fertile tissue (the gills, tubes, spines, etc.) to the stipe of the fungus in which the attachment is typically perpendicular into the stipe, i.e. without dipping towards the pileus or down the stipe.
Adult leaves Adventitious Buds Adventitious buds form along a stem, generally after the stem has had an injury. This is a survival response for the plant. These adventitious buds will differentiate either into roots or shoots depending upon whether they are above or below ground. This is what allows gardners to plant a cutting of a stem and it will grow up into a mature plant.