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  -