_Nerve._ A simple or unbranched vein or slender rib.

_Node._ The place upon a stem which normally bears a leaf or whorl of leaves.

_Nodose._ Knotty or k.n.o.bby.

_Nucleus._ The germ-cell of the ovule, which by fertilization becomes the seed; the kernel of a seed.

_Numerous._ Indefinite in number.

_Nut._ A hard indehiscent 1-celled and 1-seeded fruit, though usually resulting from a compound ovary.

_Nutlet._ A diminutive nut.

_Ob-_. A Latin prefix, usually carrying the idea of inversion.

_Obcompressed._ Compressed dorso-ventrally instead of laterally.

_Obconically._ Inversely conical, having the attachment at the apex.

_Obcordate._ Inverted heart-shaped.

_Oblanceolate._ Lanceolate with the broadest part toward the apex.

_Oblique._ Unequal-sided or slanting.

_Oblong._ Considerably longer than broad and with nearly parallel sides.

_Obovate._ Inverted ovate.

_Obovoid._ Having the form of an inverted egg.

_Obsolete._ Not evident; rudimentary.

_Obtuse._ Blunt or rounded at the end.

_Ocrea._ A leggin-shaped or tubular stipule.

_Ocreate._ Having sheathing stipules.

_Ochroleucous._ Yellowish-white.

_Officinal._ Of the shops; used in medicine or the arts.

_Oospore._ The fertilized nucleus or germ-cell of the archegonium in Cryptogams, from which the new plant is directly developed.

_Opaque._ Dull; not smooth and shining.

_Operculate._ Furnished with a lid.

_Operculum._ A lid; the upper portion of a circ.u.mscissile capsule.

_Orbicular._ Circular.

_Orthotropous_ (ovule or seed). Erect, with the orifice or micropyle at the apex.

_Oval._, Broadly elliptical.

_Ovary._ The part of the pistil that contains the ovules.

_Ovate._ Egg-shaped; having an outline like that of an egg, with the broader end downward.

_Ovoid._ A solid with an oval outline.

_Ovule._ The body which after fertilization becomes the seed.

_Ovuliferous._ Bearing ovules.

_Palate._ A rounded projection of the lower lip of a personate corolla, closing the throat.

_Paleaceous._ Chaffy.

_Palet._ The upper thin chaffy or hyaline bract which with the glume encloses the flower in Gra.s.ses.

_Palmate_ (leaf). Radiately lobed or divided.

_Palmately._ In a palmate manner.

_Panicle._ A loose irregularly compound inflorescence with pedicellate flowers.

_Panicled, Paniculate._ Borne in a panicle; resembling a panicle.

_Papilionaceous_ (corolla). Having a standard, wings, and keel, as in the peculiar corolla of many Leguminosae.

_Papillose._ Bearing minute nipple-shaped projections.

_Pappus._ The modified calyx-limb in Compositae, forming a crown of very various character at the summit of the achene.

_Parasitic._ Growing on and deriving nourishment from another plant.

_Parietal._ Borne on or pertaining to the wall or inner surface of a capsule.

_Parted._ Cleft nearly but not quite to the base.

_Partial._ Of secondary rank.

_Pectinate._ Pinnatifid with narrow closely set segments; comb-like.