VEGETABLE CYTOLOGY 
79 
Characteristics of Important Commercial Starches 
Potato Starch (Solatium tuberosum) 
Mostly simple, conchoidal or ellip¬ 
soidal, with occasional spheroidal 
and two- to three-compound grains. 
Size: 5 to 125/x 
Hilum: circular, at smaller end of 
grain. 
Lamellae: concentric and eccentric. 
Polarization cross very distinct; beau¬ 
tiful play of colors with selenite 
plate. 
Maranta Starch (Maranta 
arundinacea) 
Ellipsoidal to ovoid. 
Simple. 
Size: 10 to 65 n. 
Hilum: a transverse or crescent¬ 
shaped cleft in center or near 
broad end of grain. 
Lamellae: usually indistinct. 
Polarization cross very distinct; fine 
play of colors with selenite plate. 
Com Starch (Zea Mays) 
Polygonal to rounded. 
10 to 35^. Most grains over 15^ 
in diameter. 
Simple. 
Hilum: circular or a two- to five- 
rayed cleft. 
Lamellae: indistinct. 
Polarization cross distinct but no 
marked play of color with selenite 
plate. 
Rice Starch (Oryza sativa ) 
Polygonal.. 
2 to 10/i in diameter. 
Simple or two- to many-compound. 
Hilum: usually indistinct, occasion¬ 
ally a central cleft. 
Lamellae: indistinct. 
Polarization cross distinct but no 
play of colors with selenite plate. 
Wheat Starch (Triticum sativum) 
Circular grains appearing lenticular 
shaped on edge view; simple. 
Large grains 28 to 45^ in diameter. 
Hilum: Central, appearing as dot, 
but usually indistinct. 
Lamellae: generally indistinct, when 
present concentric. 
Polarization cross indistinct; no 
play of colors with selenite plate. 
Rye Starch (Secale cereale) 
Grains having a similar shape to 
those of wheat starch but many 
larger; simple. 
Large grains 20 to 52^ in diameter. 
Hilum: a star-shaped central cleft or 
indistinct in some grains. 
Lamellae: concentric. 
Polarization cross distinct. 
Barley Starch (Hordeum distichon) 
Grains having a similar shape to 
those of wheat starch but fre¬ 
quently tending to bulge on one 
side and so appear sub-reniform; 
large grains smaller; simple. 
Grains appear elliptical to lemon 
shaped in edge view. Large 
grains usually 18 to 25/x, occa¬ 
sionally up to 30JU in length. 
Hilum: centric or circular or cleft, 
often indistinct. 
Lamellae: concentric, often indistinct. 
Polarization cross distinct. 
Buckwheat Starch (Fagopyrum 
esculentum) 
Grains simple and compound. 
Simple grains polygonal or rounded 
polygonal. 
