Interfoliaceous, between the leaves of a pair or whorl.
Internode, the part of a stem between two nodes, [13].
Interpetiolar, between petioles.
Interruptedly pinnate, pinnate with small leaflets intermixed with larger.
Intine, inner coat of a pollen grain.
Intrafoliaceous (stipules, &c.), placed between the leaf or petiole and the stem.
Introrse, turned or facing inwards; i. e. towards the axis of the flower, [101].
Intruse, as it were pushed inwards.
Inversed or Inverted, where the apex is in the direction opposite to that of the organ it is compared with.
Involucel, a partial or small involucre, [76].