MICROPYLE, the opening or foramen of the seed. MILLIMETRE, equal to 0.0393707 English inch. MONADELPHOUS, stamens united into one bundle by union of their filaments. MONILIFORM, beaded; cells united with interruptions, so as to resemble a string of beads. MONOCARPIC, producing flowers and fruit once during life, and then dying. MONOCHLAMYDEOUS, flowers having a single envelope. MONOCLINOUS, stamens and pistils in the same flower. MONOCOTYLEDONOUS, having one cotyledon in the embryo. MONŒCIOUS, stamens and pistils in different flowers on the same plant. MONOPETALOUS, same as gamopetalous. MONOPHYLLOUS, same as gamophyllous. MONOSEPALOUS, having one sepal or division in the calyx. Same as gamosepalous. MONSTROSITY, an abnormal development; applied more especially to double flowers. MORPHOLOGY, the study of the forms which the different organs assume, and the laws that regulate their metamorphoses. MUCILAGE, a thick viscid fluid. MUCRO, a stiff point abruptly terminating an organ. MUCRONATE, having a mucro. MUCRONULATE, having a little hard point. MURICATE, covered with firm sharp points or excrescences. MURIFORM, like bricks in a wall; applied to cells. MYCELIUM, the cellular spawn of fungi. N NAKED, applied to seeds not contained in a true ovary; also to flowers without any floral envelopes. NAPIFORM, shaped like a turnip. NATURALIZED, originally introduced by artificial means, but become apparently wild. NAVICULAR, hollowed like a boat. NECTARY, any abnormal part of a flower. It ought to be restricted to organs secreting a honey-like matter, as in the Crown Imperial. NERVATION, same as Nevation. NERVES, the veins of leaves. NETTED, applied to reticulated nevation. NODDING, drooping. NODE, the part of a stem from which the leaf-bud proceeds. NODOSE, having swollen nodes or articulations. NUCLEUS, the body which gives origin to new cells; also applied to the central cellular portion of the ovule and seed. NUCULE, female part of fructification in the _Characeæ_. NUT, any dry one-celled indehiscent fruit with hard pericarp. O OBCORDATE, inversely heart-shaped, with the divisions of the heart at the opposite end from the stalk. OBLONG, about three-fourths as long as broad. OBOVATE, reversely ovate, the broad part of the egg being uppermost. OBSOLETE, imperfectly developed or abortive; applied to the calyx when it is in the form of a rim. OBTUSE, not pointed, with a rounded or blunt termination. OCHRACEOUS, clay or ochre color. OCHREA, the sheathing stipule of _Polygonaceæ_. OFFICINAL, sold in the shops. OLERACEOUS, used as an esculent pot-herb. OLIVACEOUS, having the color of olives. OOPHORIDIUM, organ, in Lycopodiaceæ containing large spores. OPAQUE, dull, not shining. OPERCULAR, covered with a lid.