Notes on the ontogeny and structure of the seed-coat of Sclerocarya birrea (Richard) Hochst. subsp. caffra (Sonder) Kokwaro (Anacardiaceae) |
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Authors: | IRMGARD VON TEICHMAN FLS |
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Institution: | Margaretha Mes Institute for Seed Research, Department of Botany, University of Preloria, Pretoria 0002, Republic of South Africa |
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Abstract: | The pendulous, bitegmic, anatropous ovulr with dorsal raphe is suspended at the tip of a massive funicle. A group of nurellar cells with intensively staining cell walls, the hypostase sensu stricto , is present. The initially plate-like tanniniferous chalazal-nucellar tissue, with suberin and lignin impregnated cell walls represents a hypostase sensu lato . The mature seed-coat is formed by the raphe, extensive chalaza, adjacent, well-developed, cup-like hypostase sensu lato , remnants of the two integuments and a cuticular layer. The exalbuminous seed of Sclerocarya birrea suhsp. caffra (the Marula), is regarded to he a derived and phylogenetically advanced type. The undifferentiated seed-roat is very similar to that found in Lannea discolor which, like the marula, belongs to the tribe Spondieae. The similarities in the structure of the seed-coat and seed of the marula and L. discolor confirm their proposed close phylogenetir relationship. |
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Keywords: | Chalaza hypostase raphe seed |
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