Morphological adaptation to water uptake and transport in the poikilohydric moss Tortula ruralis

Abstract

Abstract In this paper different water-holding and transport adaptations to face the uneven and intermittent distribution of water in the ectohydric moss Tortula ruralis are referred to. The external conduction of water is operated by different and efficient systems (spaces between adjacent shoots, between leaves, leaves and stems, leaves and rhizoids, life form, etc.) which facilitate absorption and transport of solutions. Also epi-organ capillary systems (bases and revoluted margin of leaves, a groove, a close network of capillary channels determined by the papillae), intra-organ capillary systems (hyalocysts) and certain amount of internal conduction (conducting parenchyma, stereoma) co-operante to absorb and distribute water to the whole gametophyte. In addition, some adaptations to xerophytism and heliophytism (life form, disposition of phylloids, hair-points) are discussed.