OENU8 NELXIMBO. 



840 



GENUS NELUMBO. 



The genus Nelumbo or Nelumbium includes only two recognized species and a dozen or more 

 cultivated varieties. One of the species is American and the other Oriental. Nelumbo is popularly 

 known as the Egyptian lotus, but the lotus of the Ancient Egyptians that is figured in their statues, 

 monuments, buildings, etc., is a Nymphoea, either N. ccerulea Savigny (A'', stellata Caspary, N. scuti- 

 folia Hort.), the blue lotus of Egypt, which is a native of Egypt and Africa; or A'', lotiis Linn. (A^. 

 edulis, N. thermalis), the white lotus, also a native of Egypt. Both of these species belong to 

 the true water-lilies in contradistinction to Nelumbo, which does not. Nelumbo nucifera Gsertn. 

 (Nelumbium spedosum Willd., N. indica Pars., N. nelumbo Karst.) is the Indian lotus, a native of 

 tropical and semi-trojjical Asia and of Australia, and now widely cultivated, especially in China 

 and Japan, where the tuberous rhizomes are consumed as a food and used for the preparation of 

 Chinese arrowroot (see Marantacece, page 811). The beans of Nelumbo, known as the Pythagorean 

 bean or sacred bean of the ancients, are also used as a food. N. lutea Pers. is the American lotus or 

 water chinkapin or wankapin, and is a native of the interior and eastern parts of the United States 

 from the Great Lakes to Florida. Starches from both species were studied. 



STARCH OF NELUMBO NUCIFERA. (Plate 93, figs. 557 and 558, Chart 365.) 



Histological Characteristics. — In form the grains are simple. Aggregates consisting of two or 

 rarely three components are occasionally observed. There are a few clumps and some grains have a 

 single pressure facet. The grains are rounded and quite regular. The most conspicuous forms are 

 the rounded ovoid, ovoid, and oval; also spherical, sugar-loaf, and hemispherical, the last two being 

 comparatively xmcommon. The ovoid grains have often 

 a somewhat flattened end, suggesting the beginning of a 

 pressure facet. There are modifications of these forms, 

 such as ovoid forms with a broad and flaring end, elon- 

 gated forms approaching the pyiform type, and somewhat 

 triangular forms. Grains which are broader at the distal 

 end show decided flattening at this part. Viewed from 

 the end the grains appear spherical or ovoid. 



The hilum is a very distinct, very large, round refrac- 

 tive spot or cavity. It is eccentric usually about two- 

 fifths to one-fourth of the longitudinal axis and is in most 

 cases marked by several deep fissures, usually arranged 

 in a stellate or 3-way fashion. There is occasionally a 

 single transverse or diagonal fissure. The main fissures 

 are usually ragged and subdivided at the ends. Occasion- 

 ally there may be double hila, in which case there may 

 be a fissure between the two, indicating probably the line 

 of union of two component grains. 



The lamella are fairly distinct, rather coarse, usually 

 regular, concentric rings. Those about the hilum, and 



one or two centrally located, are apt to be coarser and more distinct than the others. They are gen- 

 erally very regular, but often show somewhat wavy outlines near the margin, and the distal lamellae 

 tend to follow the outlines of the margin of the grain. The number varies from 14 to 24 on the 

 medium-sized grains. 



The grains vary in size from about 10 to 40/i. The common size is 32^. 



Polariscopic Properties. — The figure is usually eccentric, distinct, quite clear-cut, and regular. 

 All four lines are usually distinct and fairly broad, becoming broader and less clear-cut as they 

 approach the margin. They may be bent. Occasionally double figures are seen. 



The degree of polarization is high. It is higher when the grain is seen on end, and it varies 

 somewhat in different grains, but not particularly in a given aspect of a grain. 



With selenite the quadrants are well defined, irregular in shape, and unequal in size. The colors 

 are fairly pure. 



Iodine Reactions. — ^With 0.25 per cent Lugol's solution the graii^s color fairly deeply a blue to 

 blue-violet; with 0.125 per cent solution they are only tinted. Some grains are colored more readily 



