PHARMACEUTICAL BOTANY 
SO 
Size: io to 6 sm- 
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, 
io to 35 ix. Most grains over 15/1 
in diameter. 
Simple. 
Fig. 18. — Corn Starch. ( X 500.) 
{Sayre.) 
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 n in diameter. 
Simple or two- to many-compound. 
Fig. 19. — Rice Starch. ( X 250.) 
(Sayre.) 
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 ) 
Lenticular grains appearing elliptical 
shaped on edge view; simple. 
28 to 50^ in diameter. 
Hilum: central, appearing as dot, 
usually indistinct. 
Fig. 20. — Wheat Starch. ( X 250.) 
(Sayre.) 
Lamellae: indistinct. 
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. 
20 to 6oju in diameter. 
Hilum: a star-shaped central cleft. 
Lamellae: concentric. 
Polarization cross distinct. 
Buckwheat Starch (Fagopynnn 
esculentum) 
Grains simple and compound. 
Simple grains polygonal or rounded 
polygonal. 
Compound grains more or less rod- 
shaped. 
2 to 1 5 m in diameter. 
Hilum: central. 
Lamellae: indistinct. 
Polarization cross distinct. 
