Which preposition to use with spadices

of Occurrences 4%

So fast do they grow, that they have not time to fill up the spaces between their nerves, and are, consequently full of oval holes; and so fast does its spadix of flowers expand, that (as indeed do some other Aroids) an actual genial heat and fire of passion, which may be tested by the thermometer, or even by the hand, is given off during fructification.

Which preposition to use with  spadices