Marginal:- Along, or on, the margin.
Maquis:- A scrubland vegetation of the Mediterranean region composed
primarily of leathery, broad-leaved shrubs or small trees.
Medifixed:- (of hairs or anthers) Attached at or near the middle 
Membranous:- Thin and dry, often opaque or transparent - like a membrane.
Mericarp:- A portion of a schizocarp which splits away at maturity as a
perfect fruit,
Merous:- Having a specified number of parts. e.g. "pentamerous" = 5-merous.
Midrib:- When the petiole extends into the leaf and divides the leaf into two,
Monadelphous:- In one bundle and united by the filaments
Monochasial Monochasium:- Inflorescence with a terminal flower and one
bracteole subtending a lateral flower; for compound monochasium, in which
the lateral part branches further,
Monoecious:- With all flowers bisexual or with male and female flowers on
the same plant.
Monocotyledons:- The other major grouping of the flowering plants, but a
minority of the families in this book. Monocotyledons ('monocots') have a
single seed-leaf (cotyledon). The stem vessels consists of a distinct series of
bundles or are scattered. The leaves nearly always have parallel veins.
Flowers are typically 3-parted, or multiples thereof. Although relatively few
families belong here, they are important in the region. The Amaryllidaceae,
Liliaceae, Iridaceae, Orchidaceae and Gramineae are important monocot
Mucilaginous:- Pertaining to or resembling or containing mucilage: slimy.
Herbs that have a soothing effect on inflamed mucous membranes.
Mucro:- A sharp terminal point
Mucronate:- Of or having a mucro; ending abruptly in a sharp point
Mucronate-dentate With a toothed margin and ending in a short sharp point
Mucronulate:- Ending abruptly in a very short, stiff straight point.
Muricate:- Rough with short hard pointed protuberances
Muticous:- Lacking a point or awn; blunt.
Mycorrhiza:-  An association of roots and fungi, dependent or par­tially
dependent upon one another.