Botanic characteristics
Unground Caraway
Separate mericarps from about 4 to 7 mm in length, and from 1 to 2 mm in diameter. The mericarp is oblong, curved, and tapers toward the base and apex, to which half of the stylopodium is attached. Externally, it is dark brown to weak brown and shows five lighter-colored, filiform, primary ribs, between each pair of which a secondary rib occurs on the dorsal surface.
Histology
The mericarp is nearly equilaterally pentagonal in transverse section and shows a fibrovascular bundle in each primary rib. The epicarp consists of tabular polygonal epidermal cells with thick outer walls possessing a striated cuticle and with occasional stomata. The mesocarp, located between primary rib regions, is composed of collapsed, thin-walled parenchyma normally bearing four dorsal vittae in the intervals and two commissural vittae and sometimes one or more additional vittae. The endocarp consists of broad, slightly undulate, inner epidermal cross cells that are coherent with the collapsed cells of the spermoderm. The endosperm consists of thick-walled reserve parenchyma containing fixed oil and aleurone grains up to 10 µm in diameter, the latter with embedded rosette aggregates of calcium oxalate up to 4 µm in diameter. An embryo is embedded in the upper end of the endosperm.
Powdered Caraway
Moderate yellowish brown to light olive brown. It shows fragments of the epicarp with striped cuticle, numerous polyhedral endosperm cells containing aleurone grains with embedded rosette aggregates of calcium oxalate, few fragments of slightly lignified fibers and spiral vessels, fragments of cross cells of endocarp, orange to yellow fragments of vittae, and no reticulate parenchyma.