840 



STARCHES OF NYMPILBACEiE. 



STARCHES OF NYMPH/EACE^E. 



Class, Dicotyledones. Order, Ranales. Family, Nymphaeacese. 

 represented: Nymphsea and Nelumbo. 



Genera 



This family includes 8 genera and 53 species of water-lilies, widely distributed in temperate and 

 tropical waters. It is typified by the genus Nymphoea. 



GENUS NYMPH/EA. 



This genus includes over 30 species and there is a large number of varieties and hybrids. Cas- 

 pary divides the Nymphcea into two sections, which in turn are subdivided into 6 subgenera: 



(1) Lotos, including two or three species native of Southern Europe, Asia and Africa. 



(2) Hydrocallis, including about nine species native of tropical America. 



(3) Xanthantha, including two American species. 



(4) Castalia, including about six species native of Europe, Asia, and America. 



(5) Brachyceras, including about twelve species distributed in the tropics of both worlds. 



(6) Anecphya, including but a single Australian species. 



Hybridization has been carried on quite extensively, so that a large number of garden varieties 

 have been obtained in this way. Starches from six sources were prepared, all of them being refer- 

 able to Castalia. The specimens include the following: A'', alba Linn.; N. marliacea var. albida; 

 N. marliacea var. car-ma; N. gladstoniana; N. odorata Ait., the sweet-scented water-lily; and N. 

 odorata var. rosea Pursh., the Cape Cod water-lily or pond-lily. N. alba is a well-known species from 

 Europe and Siberia, and the next three are recorded as garden varieties of N. alba and N. alba var. 

 rosea and are very much ahke. N. odorata is common in the eastern United States, and its variety 

 is referred to Massachusetts. 



STARCH OF NYMPH^A ALBA. (Plate 91, fig. 545. Chart 359.) 



Histological Characteristics. — In form the grains are usually simple. There are a few compound 

 grains and small aggregates, which commonly are in the form of doublets or triplets. Pressure 

 facets are often found upon the isolated grains. There are some clumps. The surface of the grains 

 is usually more or less irregular, owing chiefly to the depo- 

 sition of secondary lamellae placed at varying angles to 

 the original set or to depressions of the margin. The 

 conspicuous forms of the simple grains are ovoid, oval, 

 and roimd; also dome-shaped to hemispherical, trian- 

 gular with roimded angles, irregular ovoid or oval with 

 squared end, elliptical, and various irregular forms. The 

 grains are not flattened in any diameter. 



The hilum is a distinct round, or occasionally lentic- 

 ular, refractive spot. It is centric or nearly so in the 

 round forms, and eccentric from very slightly to one- 

 third, usually about two-fifths, of the longitudinal axis 

 in other grains. Two hila are sometimes found in the 

 simple grains. The hilum is often fissured; there may 

 be either a single transverse fissure, two short fissures 

 intersecting each other in the form of a cross or several 

 arranged in a stellate figure, or two or three short radial 

 fissures proceeding from the hilum. It is situated in the 

 broader end of the ovoid type. 



The lamelUz are frequently not distinct directly around the hilum, but in some grains are coarse 

 and plainly observed throughout the entire grain. They form complete rings around the hilum, tend 

 to have the form of the grain not far from the hilum, and are sometimes undulating in outline as 

 they approach the distal margin. One especially prominent lamella is frequently found at about half 

 the distance between the hilum and the distal end. Secondary sets of lamellae are not uncommon. 

 The number of lamellae varies from 8 to 15 in some of the larger grains. 



Chart No. 359. 



MINUTES 



Curve of Reaction-Intensities of Starch of Nymphaca alba. 



