=imbricate=, overlapping like the tiles of a roof. =imparipinnate=, pinnate with an uneven number of leaflets. =indefinite=, without fixed number, usually meaning a large number (of sepals, petals, stamens, etc.). =indehiscent=, applied to fruits which do not split to allow the seed to escape. =inferior=, applied to an ovary means that it is enclosed in and adherent to the calyx. =inflorescence=, the manner in which flowers are arranged on a plant. =infundibuliform=, funnel-shaped. =internode=, the portion of a stem between the point of attachment of two successive leaves, if alternate leaves, or pairs of leaves, if they are opposite. =interrupted=, when applied to an inflorescence means that portion of the axis bears no flowers although there are some both above and below. =involucel=, the involucre of a secondary umbel. =involucre=, a whorl of bracts, sometimes united and sometimes in several rows below an inflorescence or an individual flower. =involute=, rolled from the back, _e.g._, towards the upper surface of a leaf. =irregular=, applied to a flower which cannot be divided into two equal sections in whatever direction from above it is cut. =-jugate=, in pairs, _e.g._, bijugate in 2 pairs, trijugate in 3 pairs, multijugate in many pairs, etc. =keel=, the (more or less) united two lower petals in =Papilionaceæ=; also applied to straight longitudinal nerves on bracts, sepals or petals. =labiate=, lipped, referring to the shape of the corolla or perianth. =laciniate=, cut about, ragged, applied to leaves, the lobes of which are narrow and irregular. =lamina=, the blade or broad part of a leaf. =lanceolate=, lance-shaped, applied to leaves about three times longer than broad, broadest below the middle and tapering to the apex. =latex=, milky sap. =leaflet=, a subdivision of a compound leaf, _q.v._ =legume=, the seed-vessel of =Leguminosæ=, 1-celled and 2-valved. =lepidote=, covered with small scurfy scales. =ligulate=, strap-shaped. =ligule=, a kind of stipule embracing the stem of grasses where the sheath gives way to the blade of the leaf. =ligulifloræ=, a section of the =Compositæ=, the florets of which in a head have all a strap-shaped corolla. =limb=, the broader part of a leaf, but more commonly the broader part of the corolla above the tube, where it expands. =linear=, narrow and long with parallel margins. =lip=, a long more or less pendent corolla lobe or petal as in =Labiatæ=, =Orchidaceæ=, etc. =lobes=, the divisions of a simple leaf or calyx or corolla or fruit. =lobulate=, having minute lobes. =-locular=, divided into compartments or cells, _e.g._, trilocular = 3-celled. =lodicules=, hyaline or fleshy nerveless scales in grasses, representing the perianth of the flower. =lunate=, crescent-shaped. =lyrate=, applied to a pinnatifid leaf with a broader rounded terminal lobe and smaller, shorter ones below, _e.g._, some =Cruciferæ= and =Compositæ=.