GENERA CALATHEA AND STBOMANTHB. 



837 



Differentiation of Certain Starches of the Genus Calathea. — Continued. 



Effects of Various Reaqents. — Continued. 

 Reaction with Chromic Add. — C!ontinued. 



C. villala: Begins in all in 30 seconds; complete in all 



in 5 minutes. 

 C. wioliana: Begins in all in 30 seconds; complete in all 



in 6 minutes. 

 C. vandenheckei: Begins in all in 30 seconds; complete in 



all in 43^ minutes. 



Reaction with Pyrogallic Acid. 



C. lietzei: Begins in most in IJ^ minutes; complete in 



four-fiftlis in 8 minutes. 

 C. viltala: Begins in most in 45 seconds; complete in 



three-fourths and partial in one-fourth in 20 



minutes. 

 C. wioliana: Begins in some in IJ^ minutes; complete in 



about one-half in 22 minutes. 

 C. vandenheckei: Begins in most in 45 seconds; complete 



in four-fifths in 8 minutes. 



Effects of Various Reaoents. — Continued. 

 Reaction with Ferric Chloride. 



C. lietzei: Begins in some in a minute; complete in 13 



minutes. 

 C. vittaia: Begins in some in 45 seconds; complete in half 



in an hour, and in all in 33^ hours. 

 C. wioliana: Begins in some in a minute; complete in half 



in 1% hours, and in all in 2% hours. 

 C. vandenheckei: Begins in a few in 1 J^ minutes; complete 



in two-thirds in an hour and in all in 4J^ hours. 



Reaction with Purdy's Solution. 

 C. lietzei: Begins in some in 2 minutes; partially in a few 



in 10 minutes. 

 C. vittaia: Begins in some in 15 seconds; complete in half 



in 30 minutes. 

 C. wioliana: Begins in some in 45 seconds; partially in 



one-third in 7 minutes. 

 C. vandenheckei: Begins in some in 2 minutes; partially 



in a few in 30 minutes. 



NOTES ON THE STARCHES OF CALATHEA. 



The four Calathea starches differ sufficiently in their histological features to permit of their 

 differentiation from one another. The variations in the conspicuous forms, hilum, lamellae, and size 

 taken collectively are quite characteristic. In their reactions they may also be distinguished. It 

 will be seen that C. lietzei and C. vandenheckei are in close accord, and that C. vittaia and C. tviotiana 

 similarly agree, the chief differences between the couples being in the temperatures of gelatinization, 

 and in the chloral hydrate-iodine, chromic acid, pyrogallic, and Purdy's solution reactions. 



GENUS STROMANTHE. 



This genus includes only five species of tropical foliage plants which, as before stated, are closely 

 allied to Maranta, Calathea, Phrynium, and Thalia. Several of the species are commercially known 

 as Marantas. Starch from S. sanguinea Sonder (Maranta sanguinea Hort.), probably of Brazilian 

 nativity, was studied. 



STARCH OF STROMANTHE SANGUINEA. (Plate 91, figs. 543 and 544. Chart 355.) 



Histological Characteristics. — In form the grains are simple. There are a few small aggregates 

 and a few small clumps. A few pressure facets are noted. The surface of the grains is generally 

 quite smooth and regular. In a few grains irregularities are noted, due chiefly to single or double, 

 nipple-like projections from the distal end and occasionally to lamellated masses of starch, probably 

 added, usually to the distal end, after the rest of the grain was formed. The conspicuous forms are 

 the elongated ovoid, with the distal end slightly narrower than the proximal, and often somewhat 

 squared with a narrow depression in the center of this squared portion; and the narrow elliptical, 

 which may be straight or bent, whose proximal and distal ends are of the same size; also a few 

 obtuse-angled triangles, and among the small grains a few spherical or almost spherical forms. The 

 grains are not flattened, and when seen on end appear spherical. 



The hilum is not distinct and is often invisible. It is a small round spot, eccentric from about 

 one-third to one-sixth of the longitudinal axis and in or near the median line. It is occasionally 

 fissured, the fissure being either a small, single, curved, clean-cut, transverse line, or two small 

 lines forming a cross. There is never more than one hilum. 



The lamellce are fairly distinct, rather coarse ellipses, or segments of ellipses, which are probably 

 continuous. They usually follow the outline of the margin, but sometimes show waviness and other 

 irregularities of outline. They vary in size in different grains, and are usually coarser and more 

 distinct near the distal end than near the hilum, and in some grains one or more sets of lamellae 

 are added to or near the distal end, with their longitudinal axis forming an angle with the same axis 

 of the primary part of the grain. There are about 12 to 15 lamellae on the larger grains. 



The grains vary in size from 4 to 46/i. The common size is 30ai. 



