GLOSSARY 



659 



Metaphloem, the later-formed elements 

 of the primary phloem. 



Metaxylem, the later-formed elements 

 of the primary xylem usually char- 

 acterized by reticulate or pitted walls. 



Microgamete, the smaller of two unit- 

 ing cells or gametes, the sperm. 



MicROPYLE, the orifice leading through 

 the integuments to the nucellus. 

 This frequently persists in the seed. 



MiCROSPORANGiuM, a spotangium in 

 which microspores are developed. 



Microspore, a tetraspore from which 

 the microgametophyte develops. 



MicROSPOROPHYLL, (in angiospetms) a 

 stamen. 



Middle lamella, the isotropic inter- 

 cellular substance between two pri- 

 mary walls. 



MoNADELPHOus, (of stamcns) forming 

 a single cycle with undiverged fila- 

 ments. 



Monoecious, with staminate and car- 

 pellate flowers on the same plant. 



MoNOPODiAL, applied to a stem with a 

 single continuous axis. 



Multiple fruit, one developed from a 

 cluster of flowers. 



Napiform, turnip-shaped. 



Nectary, an organ or surface where 

 nectar is secreted. 



Node, the point on a stem from which 

 a leaf diverges. 



Nucellus, the body of an ovule, distal 

 to its integuments. 



Nucleolus, a small proteinaceous body 

 occurring in the nucleus. 



Nucleus, a specialized often more or less 

 ovoid or spherical portion of the 

 protoplast surrounded by a delicate 

 membrane, consisting of chromatin 

 variously arranged, nuclear sap, and 

 nutritive substances. It is essential 

 in metabolism, growth, reproduction, 

 and in the transmission of the deter- 

 miners of hereditary characters. 



Nut, a fruit resembling an akene but 

 with a thick hard pericarp, usually 

 developed from a compound ovary. 



Obcordate, inverted heart-shaped. 



Oblate, flattened at the poles. 



Obovate, inverted ovate. 



Ontogeny, the developmental history 

 of an individual as contrasted with a 

 race. Cf. Phytogeny. 



Opposite, (of leaves) two at one node. 



Orbicular, circular. 



Orthotropous, (of ovule) one in which 

 the nucellus is erect with the micro- 

 pyle farthest from the hilum, in a 

 straight line with it and the chalaza; 

 also called atropous. 



Ovary, the part of the carpel, or carpels 

 in a compound pistil, that contains 

 the ovules. 



Ovate, egg-shaped with the broader 

 end downward. 



Ovule, the nucellus and its integu- 

 ments. 



Palea, or palet, (in grasses) the upper 

 bract which with the lemma encloses 

 the flower. 



Palisade, the perpendicularly elongated 

 cells which commonly form the layer 

 of chlorenchyma beneath the adaxial 

 epidermis of a leaf. 



Palmate, (of leaves) radiately lobed or 

 divided. 



Panicle, a compound raceme. 



Papilionaceous, (of corolla) with a 

 standard, keel, and wings as in many 

 leguminous plants. 



Pappus, (in composites) the limb of the 

 calyx which may be capillary, bristle- 

 like, chaffy, or wanting. 



Parenchyma, simple, non-specialized 

 vegetative tissue with more or less 

 isodiametric, thin-walled cells con- 

 taining functional protoplasts. 



Parietal, (placentation) that type in 

 which the ovules are borne on the 

 ovary wall. 



