| Meristem |
A region of undifferentiated plant tissue that is capable of active division. |
| Merous |
A fixed number of parts, such as 5 sepals or 5 petals, that may be stated as 5-merous. |
| Mesophyll |
Refers to the internal layers of leaves, the cortex and pith of stems and roots, and the soft tissues of fruits. |
| Midrib |
The principal nerve that runs down the length of a leaf. |
| Mitochondria |
These are organelles, or specialised subcellular structures, that generate most of the chemical energy needed to power biochemical processes in the cell. |
| Molecule |
A group of atoms bonded chemically. |
| Monadelphous |
Arranged in one group, usually referring to stamens. See diadelphous. |
| Monoecious |
Unisexual flowers, either male or female, borne on the same tree. Refer dioecious. |
| Monopodial |
A main stem that continues to extend, having lateral branches below the growing point. Monopodial inflorescences include racemes, panicles and some umbels. |
| Montane |
Of mountainous regions. |
| Morphology |
The study of the external structure and appearance of a plant, its visible vegetative and reproductive characteristics and its growth forms and shapes. Morphology differs from plant anatomy, which is the study of the internal structures of plants. |
| Mucilage |
Slime or jelly-like excretion, being high molecular weight carbohydrate. |
| Mucro |
A short, sharp, fine point at the tip of the leaf. It is a continuation of the midrib. See apiculate. |
| Mucronate |
Having short, sharp, fine points at the tips of the leaves. See apiculate. |
| Multiveined |
Several primary veins of approximately equal thickness radiating from a single point at the base of the leaf, where the petiole attaches. See Palmately veined. |
| Multi-veined |
Several primary veins of approximately equal thickness radiating from a single point at the base of the leaf, where the petiole attaches. See Palmately veined. |
| Necrosis |
The death of plant tissue. |
| Nectar |
Sweet fluid secretions by glands in flowers or extra-floral nectaries to attract pollinators. Nectar mainly contains fructose, glucose, and sucrose. |
| Nectary |
A gland that secretes nectar. |
| Nerve |
Another term for a leaf vein. |
| Nervose |
Another term for leaf venation, or veins. |
| Net venation |
Having a network of fine veins that branch and re-join. |
| Nitrogen fixing |
The conversion by soil micro-organisms of atmospheric nitrogen into organic nitrogen compounds that are usable by the plant. |
| Node |
The point or section of a stem from which new growth arises. New growth can only arise at a node. |
| Nodose |
With knots, knotted. |
| Nodule |
Small swellings on a leaf that contain bacteria, or small knobs on a root that contain nitrogen fixing bacteria. |
| Nut |
A dry, indehiscent fruit with one seed, a protective husk and a hard shell, but no wings. A nut is similar to an achene, but its wall is significantly thickened and hardened. |
| Oblanceolate |
If referring to a leaf, a leaf that is narrowly lance-shaped and widest about two thirds up from the base. Attached to the stem by the pointed end. Compare with lanceolate, which is widest about one third up from the base. |
| Oblique |
Unequal sides at the leaf base. |
| Obovate |
If referring to a leaf, a leaf widest above the middle, toward the apex, and narrowing smoothly toward the base. Similar to an inverted teardrop shape. |
