Eco-physiological studies on Indian arid zone plants

Abstract

Plants of the Indian desert belonging to 29 families, 85 genera and 105 species of angiosperms were screened for the possible occurrence of the C₄-pathway of photosynthetic CO₂-fixation. The criteria used for screening were leaf anatomy and/or δ¹³C values. The results indicated the occurrence of the C₄-pathway in members of 3 new families (Acanthaceae, Cleomaceae, Scrophulariaceae), 10 new genera (Aerva, Anticharis, Blepharis, Elyonurus, Glossocardia ¹ , Gynandropsis, Melanocenchris, Sehima, Sesuvium, Zalaeya) and 34 new species of the angiosperms. All the grasses investigated were found to possess the C₄-pathway. Cuscuta hyalina, a phloem-parasite, growing on C₄ hosts (Tribulus, Zalaeya) also revealed δ¹³C value very close to that found in the host plants.