The Anatomical Basis for Hygroscopic Movement in Primary Rays of Daucus Carota Ssp. Carota (Apiaceae)

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Elizabeth P. Lacey, Professor (Creator)
The University of North Carolina at Greensboro (UNCG )
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Abstract: Polarization microscopy was used to examine the cause of hygroscopic movement in umbellet pe- duncles, or primary rays, of Daucus carota (Apiaceae). Net microfibril orientation of thick-walled parenchyma cells is perpendicular to the long axis of the cell. When the relative humidity rises, these parenchyma cells elongate. In contrast, net microfibril orientation of sclerified fibers is parallel to the long axis of the cell. These fibers do not elongate with increasing relative humidity. Because thick- walled parenchyma cells predominate in the abaxial half of a ray and fibers in the adaxial half, and because the long axis of both cell types is parallel to that of the whole ray, the ray bends adaxially with increasing relative humidity and abaxially with decreasing relative humidity.

Additional Information

Botanical Gazette 144(3):371-375. 1983.
Language: English
Date: 1983
Cell structure, Cellular physiology, Wild carrot, Seed dispersal, Plant physiology

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