What is "starch hyacinth"

Starch \Starch\, n. [From starch stiff, cf. G. st["a]rke, fr. stark strong.]

1. (Chem.) A widely diffused vegetable substance found especially in seeds, bulbs, and tubers, and extracted (as from potatoes, corn, rice, etc.) as a white, glistening, granular or powdery substance, without taste or smell, and giving a very peculiar creaking sound when rubbed between the fingers. It is used as a food, in the production of commercial grape sugar, for stiffening linen in laundries, in making paste, etc.

   Note: Starch is a carbohydrate, being the typical amylose, C6H10O5, and is detected by the fine blue color given to it by free iodine. It is not fermentable as such, but is changed by diastase into dextrin and maltose, and by heating with dilute acids into dextrose. Cf. Sugar, Inulin, and Lichenin.

2. Fig.: A stiff, formal manner; formality.
   --Addison.

   Starch hyacinth (Bot.), the grape hyacinth; -- so called because the flowers have the smell of boiled starch. See under Grape.

n. The grape hyacinth.