d_, attached by the middle.

_Medullary_, belonging to, or of the nature of, pith (_Medulla_); pithy.

_Medullary Rays_, the silver-grain of wood, 140, 141.

_Medullary Sheath_, a set of ducts just around the pith, 140.

_Meiostemonous_, having fewer stamens than petals.

_Membranaceous_ or _Membranous_, of the texture of membrane; thin and
soft.

_Meniscoid_, crescent-shaped.

_Mericarp_, one carpel of the fruit of an Umbelliferous plant, 121.

_Merismatic_, separating into parts by the formation of partitions
across.

_Merous_, from the Greek for part; used with numeral prefix to denote
the number of pieces in a set or circle: as _Monomerous_, of only one,
_Dimerous_, with two, _Trimerous_, with three parts (sepals, petals,
stamens, &c.) in each circle.

_Mesocarp_, the middle part of a pericarp, when that is distinguishable
into three layers, 120.

_Mesophloeum_, the middle or green bark.

_Micropyle_, the closed orifice of the seed, 110, 126.

_Microspore_, the smaller kind of spore when there are two kinds, 161.

_Midrib_, the middle or main rib of a leaf, 50.

_Milk-vessels_, 135.

_Miniate_, vermilion-colored.

_Mitriform_, mitre-shaped: in the form of a peaked cap, or one cleft at
the top.

_Moniliform_, necklace-shaped; a cylindrical body contracted at
intervals.

_Monocarpic_ (duration), flowering and seeding but once, 38.

_Monochlamydeous_, having only one floral envelope.

_Monocotyledonous_ (embryo), with only one cotyledon, 24.

_Monocotyledonous Plants_, 24. _Monocotyls_, 24.

_Monoecious_, or _Monoicous_ (flower), having stamens or pistils only,
85.

_Monogynous_ (flower), having only one pistil, or one style, 105.

_Monopetalous_ (flower), with the corolla of one piece, 89.

_Monophyllous_, one-leaved, or of one piece.

_Monos_, Greek for solitary or only one; thus _Monadelphous_, stamens
united by their filaments into one set, 99; _Monandrous_ (flower),
having only one stamen, 100.

_Monosepalous_, a calyx of one piece; i. e. with the sepals united into
one body.

_Monospermous_, one-seeded.

_Monstrosity_, an unnatural deviation from the usual structure or form.

_Morphology_, _Morphological Botany_, 9; the department of botany which
treats of the forms which an organ may assume.

_Moschate_, Musk-like in odor.

_Movements_, 149.

_Mucronate_, tipped with an abrupt short point (_Mucro_), 54.

_Mucronulate_, tipped with a minute abrupt point; a diminutive