GLOSSARY OF BOTANICAL TERMS. 227 



MESOPHLCEUM, the cellular envelope of the bark or middle layer, 



composed of prismatic cells. 

 MESOPHYLLUM, the soft internal cells of a leaf. 

 MICROPYLE, the small opening into the young ovule, the organic 



summit. " 



MIDRIB, the large vein in the middle of a leaf. 

 MONADELPHOUS, stamens united in one bundle. 

 MONILIFORM, constricted at regular intervals, as in a string of 



beads. 

 MONOCOTYLEDONS, having but one cotyledon in the embryo, if 



more, alternate. 

 MONOECIOUS, stamens and pistils in different flowers, but on the 



same plant. 



MONOS, ONE, in composition Mon and Mono. 

 MONOSEPALOUS, MONOPETALOUS, calyx or corolla formed of one 



piece. 

 MUCRONATE, terminating in a stiff point or mucro, from a broad 



MULTIFID, cut into many segments. 



MURICATE, covered with small raised points or excrescences. 



MURIFORM, cellular tissue, like bricks in a wall. 



NAKED, flowers without any floral envelopes ; seeds apparently 

 without any covering. 



NATANT, floating. 



NAVICULAR, hollowed in the form of a boat. 



NECTARY, a portion of the flower which secretes honey. 



NERVATION, arrangement of the veins in a leaf. 



NITIDUS, smooth and shining. 



NODE, that portion of a stem from which the leaves are developed. 



NODOSE, having many small knots. 



NUCLEUS, the body which gives origin to new cells ; the central 

 portion of the young ovule. 



NUCLEOLUS, a clear spot in the nucleus of cells. 



NUT, seeds with a dry hard coat, one-seeded, and seated in a cup- 

 shaped involucre, also the small. hard seed in Cyperacece. 



OB, a prefix meaning that an object is reversed. 



OBLONG, about 3 times longer than broad and obtuse at the ends. 



OBOVATE, reversely ovate. 



OBTUSE, blunt, having no point. 



OBVOLUTE, the half of a folded leaf receiving the half of another 



folded in a similar manner. 

 OCHREA, a tubular stipule sheathing the stem. 

 OPAQUE, not transparent. 

 OPPOSITE, rising from opposite points 011 the same stem, or stamens 



facing the petals. 

 ORBICULAR, a leaf nearly round. 

 ORTHOTROPAL, an ovule retaining its original position without 



