A microscopic study of mature seed coats and of the development of the seed coats of sweet clover and alfalfa, does not reveal a structure comparable to a strophiole. The seed coat is much arched and palisade layer doubled at the microphyle, but there are no openings in the palisade layer nor any excrescences or tubercles about the hilum. At the margin of the hilum where the arching of the seed coat begins abruptly, resulting in a sharp curving of the seed coat, the palisade layer is apparently weaker and more easily broken than elsewhere. This was shown by the fact that in sectioning seeds through the hilum, the seed coat broke at the rim of the hilum much oftener than elsewhere.
Proceedings of the Iowa Academy of Science
©1937 Iowa Academy of Science, Inc.
Martin, J. N.
"The Strophiole in Sweet Clover and Alfalfa Seeds,"
Proceedings of the Iowa Academy of Science, 44(1), 104-104.
Available at: https://scholarworks.uni.edu/pias/vol44/iss1/18