836 



STARCHES OF MARANTACE^. 



Differentiation of Certain Starches of the Genus Calathea. 



HiBTOLOoicAii Characteristics. 

 Conspicuous Forms. 



C. lieUei: Simple, surface somewhat irregular, rarely 

 pressure facets. Clam-shell type triangular with 

 rounded comers, oval, elliptical, almost spherical, 

 elongated dome-shaped. 



C. viUtUa: Usually simple, a few compounds and aggre- 

 gates, rarely pressure facets, surface usually some- 

 what irregular. Oval to ovoid and spherical; some 

 approach clam-shell and mussel-shell shapes. 



C. wiotiana: Simple, surface sometimes slightly irregular. 

 Oval, clam-shell-shaped, mussel-shell-shaped, tri- 

 angular with rounded comers, elliptical, flattened 

 oblong. 



C. vandenhedcei: Usually simple, few compounds and ag- 

 gregates, surface often irregular. Oval, ovoid, 

 rounded triangular, oyster-shell-shaped, mussel- 

 shell-shaped, and clam-shell-shaped. 



Hilum — Form, Number, and Position. 



C. lieUei: Form rather small, fairly distinct, round, single; 

 sometimes fissured; fisstu-es usually small, single, 

 shallow, straight or curved, transverse or longi- 

 tudinal. Position usually eccentric about 0.2 of 

 longitudinal axis. 



C viltata: Form fairly distinct, round, single or some- 

 times double; may be fissured, fissure single or 

 ragged or much branched. Position usually 

 eccentric about 0.44 to 0.40, commonly about 0.44, 

 of longitudinal axis. 



C. wioliana: Form fairly distinct, small roimd, single or 

 rarely double, no fissuration except probably in 

 injured grains. Position usually eccentric about 

 0.40 to 0.20, commonly about 0.40, of longitudinal 

 axis. 



C. vandenheckei: Form distinct, round, single; frequently 

 fissured; fissure usually short, well-marked and 

 transverse. Position eccentric 0.25 to 0.20, com- 

 monly about 0.25, of longitudinal axis. 



Lamellce — General Characteristics and Number. 



C. lielzei: Fairly distinct, rather fine, complete circles or 

 arcs, quite regular. 16 to 20 on larger grains. 



C. fitiata: Distinct, coarse, quite regular complete rings 

 around hilum; may be irregular and follow margin. 

 10 to 14 on larger grains. 



C. wioliana: Distinct, coarse, complete rings around 

 hiliun, probably incomplete near distal margin, 

 fairly regular. 12 to 16 on larger grains. 



C. vandenhixkei: Distinct, coarse, complete rings near the 

 hilum, and less coarse but more distinct near margin 

 and distal end. 8 to 23 on larger grains. 



Size. 



C. lielzei: From 4 to 32/i, commonly 22/i. 

 C. vitlaia: From 6 to 24m, commonly 20^. 

 C. wioliana: From 6 to 24//, commonly IS/i. 

 C. vandenheckei: From 8 to 46^, commonly 28^. 



PoLARiscopic Pbopebtieb. 



Figure. 



C. lielzei: Usually eccentric, fairly distinct, usually not 



clear-cut. 

 C. vUUUa: Usually centric or slightly eccentric, usually 



not very clear-cut, but regular. 

 C. wioliana: Usually eccentric, fairly clear-cut, usually 



regular. 

 C. vandenheckei: Usually eccentric, usually clear-cut and 



regular. 



Degree of Polarization. 



C. lielzei: Fair, lower than in M. arundinacea var. (Com- 

 mercial No. 1). 



PoLARiscopio Properties. — Continued, 

 Degree of Polarization. — Continued. 

 vittata: Rather high, but not so high as in M. arundi- 

 nacea var. (Commercial No. 1). 

 wiotiana: Fair, lower than in M. arundinacea var. 



(Commercial No. 1). 

 vandenheckei: Rather high, but not so high as in M. 

 arundinacea var. (Commercial No. 1). 



Polarization with Selenite — Quadrants and Colors. 



lielzei: Quadrants fairly well defined, irregular in shape 



and unequal in size. Colors not pure. 

 villata: Quadrants usually not sharply defined, quite 



irregular, unequal in size. Colors not pure. 

 wiotiana: Quadrants fairly well defined, irregular in 



shape, unequal in size. Colors fairly pure. 

 vandenheckei: Quadrants fairly well defined, irregular. 



Colors not very bright. 



Iodine Reactions. 

 Intensity and Color. 



lielzei: Fairly deep, not so deep as in Af . arundiruicea 

 var. (Commercial No. 1); blue-violet. 



vitlaia: Fair, not so deep as in M. arundinacea var. 

 (Commercial No. 1); blue- violet. 



unoliana: Deep, not quite so deep as in Af. arundi- 

 nacea var. (Commercial No. 1); violet tinged with 

 blue. 



vandenheckei: Fair, not so deep as M. arundiruicea var. 

 (Commercial No. 1); blue-violet. 



Staining Rbactions. 

 With Gentian Violet. 



lielzei: Fairly deep, not quite so deep as in M. arun- 

 dinacea var. (Commercial No. 1). 



viltata: Fair, not so deep as in M. arundinacea var. 

 (Commercial No. 1). 



iviotiana: Very light, very much less than in M. 

 arundinacea var. (Commercial No. 1). 



vandenheckei: Fair, less than in M. arundinacea var. 

 (Commercial No. 1). 



With Safranin. 



lielzei: Fairly deep, not quite so deep as in Af . arundi- 

 nacea var. (Commercial No. 1). 



vitlaia: Fair, not so deep as in Af. arundinacea var. 

 (Commercial No. 1). 



wiotiana: Very light, very much less than in Af. 

 arundinacea var. (Commercial No. 1). 



vandenheckei: Fair, less than in M. arundinacea var. 

 (Commercial No. 1). 



Temperature op Gelatinization. 



lielzei: 78 to 79° C, mean 75.5°. 

 vUtala: 82.5 to 84° C, mean 83.25°. 

 wioliana: 85 to 86° C, mean 85.5°. 

 vandenheckei: 77 to 78.5° C, mean 77.75°. 



Effects op Various Reagents. 

 Reaction with Chloral Hydrate-Iodine. 



lielzei: Begins in most in 2 minutes; complete in half 



in 9 minutes and in all in 20 minutes. 

 vittata: Begins in many in 15 seconds, and in all in 



V/2 minutes; complete in nearly all in 10 minutes. 

 wioliana: Begins in all in IK minutes; complete in 



all in 7 minutes. 

 vandenheckei: Begins in many in a minute; complete 



in two-thirds in 15 minutes and in nearly all in 



40 minutes. 



Reaclion with Chromic Acid, 

 lielzei: Begins in all in 45 seconds; complete in all in 

 6J^ minutes. 



