Devour (Ex) While a creature is under the effects of a xtabay's soporific pollen, the plant may, as a full-round action, occupy the same square as the sleeping creature and slowly sap the life from it. Every round the xtabay uses this ability, the affected creature must make a DC 14 Fortitude save or take 1d2 Con damage. This feeding is curiously painless, and normally isn't enough to waken a foe put to sleep by the plant. Each round this feeding continues, the sleeping victim can attempt a new DC 14 Will save to awaken. This save DC is Constitution-based.
Soporific Pollen (Ex) As a standard action, a xtabay can release sleep-inducing pollen into the air around it. Each creature within a 10-ft.-radius burst centered on the xtabay must make a DC 14 Will save or fall asleep for 1d3 minutes. A creature that succeeds on the Fortitude save cannot be affected by the same xtabay's soporific pollen for 24 hours. A creature put to sleep by this pollen can be awakened by vigorously shaking the sleeper (a standard action) or by damaging it. This is a mind-affecting sleep effect. The save DC is Constitution-based.
Each ability makes reference to both a will save and a fortitude save, but in crossed order. If I'm to take the above text as RAW, if you succeed at the Fortitude save to not be digested, you become immune to the pollen for 24 hours, and the "painless" feeding that "normally isn't enough to waken a foe" gives you Will saves to wake up.
I can't make heads nor tails of this.