The testa develops from the tissue, the integument, originally surrounding the ovule.
1969, C. W. Bennett, Seed Transmission of Plant Viruses, Alison Smith, Advances in Virus Research, Volume 14, page 224,
In tests with the Lincoln and Virginia varieties of cowpea, Crowley (1959) found that, in plants infected with bean southern mosaic virus before blossoming, the virus was present in nearly 100% of the testae and endosperms of seeds of both varieties, but could not be detected in the embryos.
2005, D. W. Dickson, D. De Waele, Nematode Parasites of Peanut, Michel Luc, Richard A. Sikora, John Bridge, Plant Parasitic Nematodes in Subtropical and Tropical Agriculture, page 419,
A. arachidis is a parasite of pods, testae, roots and hypocotyls, but not the cotyledons, embryos or other parts of the plant (Bos, 1977a; Bridge et al., 1977).
(marine biology) The external calciferous shell, or endoskeleton, of an echinoderm; the test.