TY  - JOUR
A1  - Herppich, Werner B.
A1  - Martin, Craig E.
A1  - Tötzke, Christian
A1  - Manke, Ingo
A1  - Kardjilov, Nikolay
T1  - External water transport is more important than vascular transport in the extreme atmospheric epiphyte Tillandsia usneoides (Spanish moss)
JF  - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology
N2  - Most epiphytic bromeliads, especially those in the genus Tillandsia, lack functional roots and rely on the absorption of water and nutrients by large, multicellular trichomes on the epidermal surfaces of leaves and stems. Another important function of these structures is the spread of water over the epidermal surface by capillary action between trichome "wings" and epidermal surface. Although critical for the ultimate absorption by these plants, understanding of this function of trichomes is primarily based on light microscope observations. To better understand this phenomenon, the distribution of water was followed by its attenuation of cold neutrons following application of H2O to the cut end of Tillandsia usneoides shoots. Experiments confirmed the spread of added water on the external surfaces of this "atmospheric" epiphyte. In a morphologically and physiologically similar plant lacking epidermal trichomes, water added to the cut end of a shoot clearly moved via its internal xylem and not on its epidermis. Thus, in T. usneoides, water moves primarily by capillarity among the overlapping trichomes forming a dense indumentum on shoot surfaces, while internal vascular water movement is less likely. T. usneoides, occupying xeric microhabitats, benefits from reduction of water losses by low-shoot xylem hydraulic conductivities.
KW  - bromeliads
KW  - capillarity
KW  - cold neutrons
KW  - epidermis
KW  - epiphytes
KW  - trichomes
KW  - water movement
Y1  - 2018
U6  - https://doi.org/10.1111/pce.13496
SN  - 0140-7791
SN  - 1365-3040
VL  - 42
IS  - 5
SP  - 1645
EP  - 1656
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Martin, Craig E.
A1  - Herppich, Werner B.
A1  - Roscher, Yvonne
A1  - Burkart, Michael
T1  - Relationships between leaf succulence and Crassulacean acid metabolism in the genus Sansevieria (Asparagaceae)
JF  - Flora : morphology, distribution, functional ecology of plants
N2  - Relationships between different measures of succulence and Crassulacean acid metabolism (CAM; defined here as nocturnal increases in tissue acidity) were investigated in leaves of ten species of Sansevieria under greenhouse conditions. CAM was found in seven of the ten species investigated, and CAM correlated negatively with leaf thickness and leaf hydrenchyma/chlorenchyma ratio. Similarly, CAM correlated negatively with leaf water content, but only when expressed on a fresh mass basis. CAM was not correlated with "mesophyll succulence", but weakly with leaf chlorophyll concentration. These results indicate that CAM is associated more with "all-cell succulence" and not with the amount of leaf hydrenchyma in the genus Sansevieria. The findings of this study emphasize the importance of defining the nature of "leaf succulence" in studies of photosynthetic pathways and leaf morphology. Evidence is also provided that CAM and succulence arose multiple times in the genus Sansevieria.
KW  - Anatomy
KW  - CAM
KW  - Chlorenchyma
KW  - Chlorophyll
KW  - Hydrenchyma
KW  - Morphology
KW  - Phylogeny
Y1  - 2019
U6  - https://doi.org/10.1016/j.flora.2019.151489
SN  - 0367-2530
SN  - 1618-0585
VL  - 261
PB  - Elsevier
CY  - München
ER  -