NATIVE PLANTS 



NECTARINE 



2115 



tions of living had become established. Peo])le had 

 ontRrowni the desire to remove. They appreciated their 

 own plants and also those from the New World. Ameri- 

 can plants attracted attention in Euroi)C rather than 

 in .\meri<'a. 



Twenty-five years ago, the writer made a censvis of 

 indigenous American jjlants known to have been 

 introduced to cultivation. The statistics were pub- 

 lished in "Annals of Horticulture for 1S91." It was 

 found "that there are in North America, north of Mex- 

 ico, about 10, 1 .50 known .species of native 

 plants, distributed in 1,.555 genera and 

 11)8 families. Of these, 2,416 species are 

 recorded in this census, representing 769 

 genera and 133 families. Of this mnnbcr, 

 1,929 species are now offered for sale in 

 America; 1,500 have been introduced into . 

 England, of which 487 are not in cultiva-' 

 tion in this country." All these species 

 are there catalogued. The only other 

 account of the entire cultivated flora is 

 that which was compOed in the "Cj'clo- 

 pedia of .'Vmerican Horticulture," 1900- 

 1902, and for which the lists of twenty-five 

 years ago were a preparation. That Cyclopedia de- 

 scribed 2,419 species of plants native to North America 

 north of Mexico. A brief sketch of the history of recent 

 efforts toward the introduction of native plants is given 

 in the preface to the catalogue of 1891. 



Formerly, the term "American plants" had a tech- 

 nical meaning in England. WiUiam Paul in his book 

 on "American Plants," pubU.shed in London in 1858, 

 writes as follows: "The history of American plants may 

 be briefly told. The term is popularly applied to several 

 genera, princijially belonging to the natural order 

 Ericaceae. They are generally 'evergreen,' producing 

 their flowers for the most part in the months of May and 

 June." The book is devoted largely to rhododendrons, 

 azaleas and kahuias, although European and other 

 heaths are included. 



There is a strong tendency toward the production of 

 peculiarly American tjTies and races even in species 

 domesticated from other countries, as of the carnation 

 and sweet pea. As .\merican plant-breeders give greater 

 attention to native species, the divergencies between the 

 horticulture of the Old World and that of the New 

 World will be accentuated. The recent multiplication 

 of books about native plants has stimulated interest in 

 the indigenous resources. L_ fj. B. 



NAUMBtlRGIA: Lyaimachia. 



NAUTILOC ALYX (apparently nauHlus-sha'ped calyx) . 

 Grsncri()n:i'. Herbs of Trop. S. Amer., usually referred 

 to Episi'ca, but lately sejiarated and re-defined by 

 Sprague (Kew Bull. 1912, 85). As now constituted, it 

 comi)rises species named in Episcea and Alloplectus, 

 9 being included altogether. Two of these may be 

 mentioned here, although apparentlj' n(jt in the Ameri- 

 can trade. The species of Nautilocalyx have the gen- 

 eral habit and appearance of Episcea, but differ in 

 having ovules on the inner surface only of the placental 

 plates rather than on both surfaces. They are distin- 

 guished from Alloplectus in being herbs rather than 

 shrubs and undershrubs, and in bearing a larger corolla- 

 limb. 



.V. Forgctii, Sprague lAUoph'rtux Forgilii, Sjjragiie). 

 Fls. pale yellow, corolla hairj' outside, the calyx-segms. 

 much shorter th.an the corolla-tube: Ivs. with very 

 wavy margins, somewhat truncate at base, green above 

 and red along the ribs and veins beneath; petioles 2 in. 

 or less long, villous. Peru. A', pdllidux, Sprague (AlU)- 

 ■plrrhin priltidtix, Sprague). Fls. creamy white, the 

 corolla h.airv outside and the front part of the tube 



Cur[)le-striped inside and the back part with broad 

 and of purple blotches: Ivs. gradually narrowed to 



base, nearly glabrous above, 

 beneath. Peru. B.M. 8519. 



minutely puberulous 

 L. H. B. 



NECTAR. Most flowers pollinated by insects possess 

 nectar-glands, simple or composite, located upon some 

 part of the floral structures. To designate nectar by 

 its chief constituent would be simply to call it a sugar 

 solution, more or less watery or dense, depending upon 

 the flower, or upon the conditions under which i)ro- 

 duced. However, several sugars may be jircsent, as well 



24S2. Various forms of nectaries. Left, the nectar-spurs of Linaria vulgaris; 

 the cusliion-like nectaries in a grape flower; nectaries of columbine; right, the 

 nectar-scales on petals of ranunculus. 



as small quantities of other substances. Just as in 

 honey, the predominant form is fruit-sugar, with cane- 

 sugar next in importance, and always with small 

 amounts of aromatic substances yielding the odor and 

 affecting the taste of the jirotluct. Sometimes muci- 

 laginous substances are present. Honey contains less 

 water than nectar, also other aromatic compounds and 

 small amounts of waxes and jjoUen. The abundant 

 secretion of nectar is, to a large extent, dejjendent upon 

 external conditions, and usually is favored by condi- 

 tions inducing the perfection of the flowers. 



Nectaries occur on various parts of the flowers, often 

 about the base of one or more petals, or even stamens; 

 again, they may take the form of glandular protuber- 

 ances or ridges arranged between any of the whorls 

 of floral members; while the most interesting and 

 conspicuous modifications involving the nectaries are 

 those in which one or more of the i)etals or other floral 

 leaves may be changed into pockets, spurs, or recep- 

 tacles. Some of the interesting types of modification 

 may be noticed in the violet, columbine, nasturtium, 

 and certain orchids. An extreme fonn is found in a 

 Madagascar orchid, angrai'cum, in wliich the nectar- 

 tube may be 6 inches long. Various nectaries are shown 

 in Fig. 2452. In all cases, the nectar is secreted from 

 glandular cells located either sujjerficially or more 

 deeply in the tissues, antl in the latter case connected 

 with the receptacle by nectar-ducts. The secreting 

 cells may be confined to a single small spot or may be 

 spread over a larger area or zone. 



The development of the curious and complicated 

 nectaries referred to indicates a remarkable adjustment 

 for insect pollination, and whatever may be the immedi- 

 ate explanation of the development of these stnictures, 

 they .serve a most useful jiurpose in effecting cross- 

 pollination. It is necessary to add, however, that the 

 secretion of sugary liquids by plants is not confined to 

 nectaries, and oftentimes the relation of these secre- 

 tions to any useful purpose is not clear. The jjroduc- 

 tion of "honey-dew" by certain plaiits, noniially or 

 through the incitation of ai)lii<l pmictures, is allied to 

 nectar-secretion. The opportunities detennining the 

 excretion of sugars by nectaries have been considerably 

 studied by physiologists; but, for these facts, the reatler 

 must seek information in i)apers dealing more exten- 

 sively with the osmotic properties of cells, as the subject 

 is too technical for <liscussion here, jj y[ Ddggar. 



NECTARINE, a .smooth-skinned peach (Prunus 

 Peralca var. nuciper.fica). Fig. 2453. It was fonnerly 

 thought to be a distinct siiecics of plant. By DeCan- 

 dolle it was called Persica Ixvis. Roemer in 1847 made 



