Anatomical structure of differently originated seed envelopes in one-seeded indehiscent fruits of Urticaceae and Asteraceae members is studied using light and scanning electron microscopes. It was found that in anthoc...Anatomical structure of differently originated seed envelopes in one-seeded indehiscent fruits of Urticaceae and Asteraceae members is studied using light and scanning electron microscopes. It was found that in anthocarps and involucrate fruits of both families the relations between the primary （pericarp） and secondary fruit envelopes （perianth and/or involucre） were composed under complexification （union） type, and not as substitution. Numerous examples of non-homologous resemblance in fruit envelope structure indicate a high degree of adaptability of certain histological types, recurring on a different morphological basis in different phyletic lines within a family. These tissue complexes represent widely occurring types of the pericarp （Utricaceae） or pericarp and seed coat tissue union （Asteraceae）. This evolutionary repetition or pseudocyclic resemblance is apparently another common regularity of one-seeded indehiscent fruits evolution in addition to those enumerated in general by Zohary （1950）.展开更多
文摘Anatomical structure of differently originated seed envelopes in one-seeded indehiscent fruits of Urticaceae and Asteraceae members is studied using light and scanning electron microscopes. It was found that in anthocarps and involucrate fruits of both families the relations between the primary （pericarp） and secondary fruit envelopes （perianth and/or involucre） were composed under complexification （union） type, and not as substitution. Numerous examples of non-homologous resemblance in fruit envelope structure indicate a high degree of adaptability of certain histological types, recurring on a different morphological basis in different phyletic lines within a family. These tissue complexes represent widely occurring types of the pericarp （Utricaceae） or pericarp and seed coat tissue union （Asteraceae）. This evolutionary repetition or pseudocyclic resemblance is apparently another common regularity of one-seeded indehiscent fruits evolution in addition to those enumerated in general by Zohary （1950）.
