imbricate (2 images): arranged in a tight spiral, so that the outermost member has both edges exposed, and at least the innermost member has both edges covered; a shingled arrangement.

incised: rather deeply and sharply (and often irregularly) cut.

included (3 images): contained within an envelope, not projecting beyond it.

incumbent: cotyledon position, lying edgewise against the folded radicle in the seed (see accumbent).

indehiscent: not dehiscent, remaining closed at maturity.

indeterminate inflorescence: one that blooms from the bottom or the outside toward the top or center, so that it might continue to elongate and produce new flowers indefinitely.

indument (2 images): the epidermal appendages of a plant considered collectively, as its pubescence.

induplicate: valvate, with the margins infolded.

indurated: hardened.

indusium (12 images): an epidermal outgrowth or reflexed and modified leaf margin that covers the sori of many ferns.

inferior ovary (13 images): one with the other flower parts attached to the top of ovary and projecting beyond it.

inflorescence (6 images): a flower cluster of a plant, or the arrangement of the flowers on the axis.

internode: the part of a stem between 2 adjacent nodes.

intrastaminal: within (as opposed to outside of) the androecium.

introduced: intentionally or unintentionally brought in from another area; not native.

introrse: turned toward the inside, or facing inward.

involucel (4 images): diminutive of involucre.

involucre (50 images): a set of bracts beneath an inflorescence; any set of structures that surrounds the base of another structure.

involute: with edges rolled back.

irregular flower: one in which the petals (less often the sepals) are dissimilar in form or orientation.

isodiametric: more or less spherical or polyhedral.