Glossary - general

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Nacreous – with a pearly sheen

Naked – (1) (of stem) without leaves; (2) (of flower) without calyx or corolla

Napiform, napoid root – shaped like a turnip, i.e. broadly ovoid and tapering to a point

Navicular, naviculiform – boat-shaped, like the bow of a pirogue or canoe

Nectar – sweet fluid extruded by glands; in flowers this is collected or eaten by animals

Nectar disc – nectariferous disc; nectar-secreting floral disc surrounding the ovary

Nectar guides – lines or blotches of colour, leading to nectar-providing zones of the plant, usually in the flower

Nectariferous – with nectar, nectary or nectaries

Nectarostomata– sap holes, specialized stomata, through which nectar is exuded

Nectar scale – scale-like structure secreting nectar through nectarostomata

Nectary – a multicellular glandular structure in which nectar is produced and from which nectar is secreted

Nectaries – nectar secreting organs; classification according to the histology: epithelial nectaries (secretion through the entire surface), trichomatous nectaries (secretion confined to glandular heads of trichomes), mesenchymatous nectaries (secretion being discharged via sap holes) – classification according to the position in the flower and the origin: septal nectaries (widespread in monocotyledons), gynostegial nectaries (Apocynaceae), phyllodial nectaries, androphyllominous nectaries, axial (receptacular) nectaries (all major clades of rosids except Fagales), gynoecial nectaries (nearly all major clades of asterids)

Nervose – full of nerves, prominently veined

Net-veined – see Reticulate

Nitrogen-fixing – bacteria converting atmospheric nitrogen into organic compounds which can be taken up by plants

Nexine (of pollen grains) – the inner, non-sculptured part of the exine lying below the sexine

Nodal – relating to the node

Nodal plexus – in many monocotyledons having stems with nodes (e.g. Poaceae and Restionaceae), the number of anastomosing vascular bundles at the nodes is so large that a nodal plexus of intermingled bundles is produced, which may extend across the stem, becoming increased by the insertion of numerous leaf traces from the axillary buds; the leaf traces may continue downwards from their points of entry into the stem for a complete internode before joining the nodal plexus below

Node – the area of a stem where a leaf is attached, or where a leaf used to be attached

Nodose – knobbly

Nodular – with small knobs or knots

Non-dispersive protein bodies (of sieve tube cells) – see Dispersive protein bodies

Notched – with a nick or cut from an otherwise entire edge

Nucellar beak (of ovule) – megasporangial beak; a structure, in which megasporangial tissue protrudes through the micropyle

Nucellar cap (of ovule) – megasporangial cap; a structure, in which the epidermal cells at the apex of the ovule, above the megasporocyte(s) and megagametophyte, divide periclinally – see Pseudocrassinucellar ovule

Nucellus – see Megasporangium

Nuclear endosperm – multiple free nuclear divisions take place and a cell wall (when produced) is formed following a number of free nuclear divisions

Nut – one-seeded indehiscent fruit, with a hard, dry pericarp (the shell); derived from a one-locular usually syncarpous ovary – see Achene

Nutant – nodding

Nutating – the revolutions of the growing tip

Nutlet – a little nut, achene; (Cyperaceae) hardened, usually minute, single-seeded fruit, the surface of which may be smooth to variously patterned and a diagnostic character for many species