Lobe. Any division of an organ, especially if rounded.

Lobed. Provided with a lobe or lobes. Page [xiii.]

Lustrous. Glossy; shining.

Membranaceous. Thin and somewhat translucent.

Midrib. The central vein of a leaf or leaflet.

Monoecious. Unisexual, with staminate and pistillate flowers on the same individual.

Mucilaginous. Slimy; resembling or secreting mucilage or gum.

Mucronate. Tipped with a small, abrupt point. Page [xii.]

Naked. Lacking organs or parts which are normally present in related species or genera.

Naturalized. Said of introduced plants which are reproducing by self-sown seeds.