22 



MISC. PUBLICATION 110, U. S. DEPT. OF AGRICULTURE 



tractive to insects, to which the 

 floral perfume is largely or some- 

 times wholly due, and from which 

 bees derive honey. 



Nectariferous: Nectar bearing or pro- 

 ducing; secreting nectar, as a nec- 

 tary. 



Nectary: A gland, usually situated at 

 or near the base of a corolla or 

 perianth, or one of its parts, which 

 secretes nectar. 



Nerve : A name for ribs or veins, when 

 unbranched and approximately par- 

 allel, applied especially in the case 

 of leaves and the chaffy bracts 

 (glumes, lemmas, and paleas) of 

 grass flowers. The terms " nerve " 

 and " vein " in botany, of course, are 

 wholly different in meaning from 

 the same terms used in zoology and 

 human anatomy. 



Nerved: Provided with nerves, as a 

 1-nervecl glume. 



Node: A joint or knot. Said especially 

 of stems, whose nodes or joints are 

 enlarged, often dark colored, and are 

 the points whence leaves often 

 spring. 



Nom. nov.: New name (Latin, nomen 

 novum), i. e., a name, hitherto un- 

 published, substituted for one in 

 general use but ascertained to be 

 untenable. 



Nom. nud. : See nomen nudum. 



Nomen conservandum : Literally, a 

 conserved name. A name retained 

 in Latin plant (or animal) nomen- 

 clature regardless of priority. Nom- 

 ina conservanda are rejected by the 

 American Code of Botanical Nomen- 

 clature (used by the United States 

 Department of Agriculture, New 

 York Botanical Garden, Leland 

 Stanford University, etc.) but are 

 admitted under the International 

 Code (used in Europe, the Gray 

 Herbarium of Harvard University, 

 the University of California, etc.) 

 Thus, under the Paris (Interna- 

 tional) Code, Glyceria R. Brown 

 (1810), although published 47 years 

 after Panicularia Heister (1763), is 

 retained for the manna grasses as 

 a nomen conservandum. Nomina 

 conservanda usually have a history 

 behind them of long usage (possibly 

 pre-Linnaean), acceptance by the 

 great botanical figures of the past, 

 better and fuller publication, ques- 

 tions of taste and propriety, etc. 



Nomen nudum (pi. -ma nuda) : Liter- 

 ally, a naked name, i. e., a name 

 only; a plant name published with- 

 out any description or figure, and 

 hence which can not be tied in with 



assurance to any plant or plant 

 group. Nomina nuda are very prop- 

 erly rejected by all codes. For ex- 

 ample, in the Flora of Washington 

 is published, without description, a 

 new subspecies of mistletoe, Razoam- 

 ofskya douglasii laricis ; such a name 

 is a nomen nudum. Nomen seminu- 

 dum is a term used to designate a 

 name published with only a word or 

 two. or a description otherwise 

 wholly inadequate. 



Nucleus: The organ of a plant or ani- 

 mal cell which is essential in ana- 

 bolism, growth, reproduction, and 

 heredity. 



Nut: A nonsplitting (indehiscent) 1- 

 seeded fruit, with hard woody shell 

 (pericarp), and developed from an 

 inferior, several to many carpelled 

 ovary. In popular usage almonds, 

 peanuts, and Brazil nuts are nuts, 

 but they are not so botanically ; an 

 almond is a drupe (close akin to a 

 peach ) ; a peanut, a legume ; while 

 the fruit of the Brazil-nut tree (Ber- 

 tholletm excelsa) is a sort of large, 

 woody-shelled capsule (pyxis) con- 

 taining nutlike seeds. 



Nutlet : A small nut or nutlike fruit or 

 seed. (Fig. 42.) For example, the 

 fruits of the borage, verbena, and 

 mint families are nutlets. 



Nyctitropism: The tendency of some 

 leaves and other plant organs to 

 assume certain positions at night 

 or in darkness; familiar examples 

 are seen in the drooping leaflets of 

 clovers and locusts as night ap- 

 proaches. 



Ob-: A prefix (Latin) signifying in an 

 opposite direction or other reversion. 



Obcordate: Reverse heart shaped; 

 with the broader, notched ends for- 

 wards or upper- 

 most, as in the 

 leaflets of oxalis 

 and white clover. 

 (Fig. 43.) 



Oblanceolate : Re- 

 verse lance 

 shaped (lanceo- 

 late) ; with the 

 narrowed, taper- 

 ing part down- 

 ward, and the 

 broader end fore- 

 most. (Fig. 38, 

 C.) 



Oblique: Unequal sided; slanting. 



Oblong: About two to four times longer 

 than broad, and with the sides, 

 though gently rounded, approxi- 

 mately parallel. (Fig. 44, A.) 



Figure 43. — Ob- 

 cordate leaf 



