Survival strategies under extreme and complex environmental conditions: The aquatic resurrection plant Chamaegigas intrepidus

• Published in: Flora. Morphologie, Geobotanik, Oekophysiologie Vol. 196; no. 4; pp. 245 - 260
• Main Authors: Heilmeier, H., Hartung, W.
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 2001
• Subjects: abscisic acid; anatomy; carbohydrates; desiccation; limnology; Namibia; nitrogen nutrition; poikilohydric cormophytes; desiccation; carbohydrates; poikilohydric cormophytes; limnology; anatomy; Namibia; abscisic acid; nitrogen nutrition
• ISSN: 0367-2530; 1618-0585
• DOI: 10.1016/S0367-2530(17)30054-3

Chamaegigas intrepidus Dinter is a tiny poikilohydric member of the Scrophulariaceae growing endemically in ephemeral rock pools on granite outcrops in Central Namibia. Habitat conditions are characterised by (1) frequent and fast desiccation and rehydration during the rainy summer season, (2) complete dehydration during the dry winter season lasting up to 11 months, (3) intensive solar irradiation and high temperatures during the dry season, (4) diurnal oscillations of pH in the pool water up to 6 units, (5) extreme nutrient deficiencies, especially nitrogen. Anatomical, biochemical and physiological adaptations to this complex of extreme environmental conditions are discussed such as contractive xylem, accumulation of abscisic acid, dehydrins and carbohydrates during desiccation, and the role of amino acids, ammonium, urea and urease for nitrogen nutrition.