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The upside-down water collection system of Syntrichia caninervis


Desert plants possess highly evolved water conservation and transport systems, from the root structures that maximize absorption of scarce ground water15, to the minimization of leaf surface area6 to enhance water retention. Recent attention has focused on leaf structures that are adapted to collect water and promote nucleation from humid air79. Syntrichia caninervis Mitt. (Pottiaceae) is one of the most abundant desert mosses in the world and thrives in an extreme environment with multiple but limited water resources (such as dew, fog, snow and rain), yet the mechanisms for water collection and transport have never been completely revealed. S. caninervis has a unique adaptation: it uses a tiny hair (awn) on the end of each leaf to collect water, in addition to that collected by the leaves themselves. Here we show that the unique multiscale structures of the hair are equipped to collect and transport water in four modes: nucleation of water droplets and films on the leaf hair from humid atmospheres; collection of fog droplets on leaf hairs; collection of splash water from raindrops; and transportation of the acquired water to the leaf itself. Fluid nucleation is accomplished in nanostructures, whereas fog droplets are gathered in areas where a high density of small barbs are present and then quickly transported to the leaf at the base of the hair. Our observations reveal nature's optimization of water collection by coupling relevant multiscale physical plant structures with multiscale sources of water.

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Figure 1: Morphology of S. caninervis and the associated awns.
Figure 2: Nucleation of dew on a moss awn surface.
Figure 3: Fog collection on an awn of S. caninervis.
Figure 4: Multifunctional hierarchical water harvest mechanisms of the moss awn.


  1. Nørgaard, T. & Dacke, M. Fog-basking behaviour and water collection efficiency in Namib desert darkling beetles. Front. Zool. 7, 23 (2010).

    Article  Google Scholar 

  2. Nørgaard, T., Ebner, M. & Dacke, M. Animal or plant: which is the better fog water collector? PloS ONE 7, e34603 (2012).

    Article  Google Scholar 

  3. Gutterman, Y. Environmental factors and survival strategies of annual plant species in the Negev Desert, Israel. Plant Species Biol. 15, 113–125 (2000).

    Article  Google Scholar 

  4. Gibbens, R. P. & Lenz, J. M. Root systems of some Chihuahuan Desert plants. J. Arid Environ. 49, 221–263 (2001).

    Article  Google Scholar 

  5. Markle, M. S. Root systems of certain desert plants. Bot. Gaz. 177–205 (1917).

    Article  Google Scholar 

  6. Beadle, N. C. W. Soil phosphate and its role in molding segments of the Australian flora and vegetation, with special reference to xeromorphy and sclerophylly. Ecology 47, 992–1007 (1966).

    Article  Google Scholar 

  7. Ju, J. et al. A multi-structural and multi-functional integrated fog collection system in cactus. Nature Commun. 3, 1247 (2012).

    Article  Google Scholar 

  8. Roth-Nebelsick, A. et al. Leaf surface structures enable the endemic Namib Desert grass Stipagrostis sabulicola to irrigate itself with fog water. J. R. Soc. Interface 9, 1965–1974 (2012).

    Article  CAS  Google Scholar 

  9. Andrews, H., Eccles, E., Schofield, W. & Badyal, J. Three-dimensional hierarchical structures for fog harvesting. Langmuir 27, 3798–3802 (2011).

    Article  CAS  Google Scholar 

  10. Zheng, Y. et al. Morphological adaptations to drought and reproductive strategy of the moss Syntrichia caninervis in the Gurbantunggut Desert, China. Arid Land Res. Manage. 25, 116–127 (2011).

    Article  Google Scholar 

  11. Bowker, M. A., Stark, L. R., McLetchie, D. N. & Mishler, B. D. Sex expression, skewed sex ratios, and microhabitat distribution in the dioecious desert moss Syntrichia caninervis (Pottiaceae). Am. J. Bot. 87, 517–526 (2000).

    Article  CAS  Google Scholar 

  12. Tao, Y. & Zhang, Y. M. Effects of leaf hair points of a desert moss on water retention and dew formation: implications for desiccation tolerance. J. Plant Res. 125, 351–360 (2012).

    Article  Google Scholar 

  13. Proctor, M. C. & Tuba, Z. Poikilohydry and homoihydry: antithesis or spectrum of possibilities? New Phytol. 156, 327–349 (2002).

    Article  Google Scholar 

  14. Proctor, M. in Bryophyte Systematics 479–509 (Academic, 1979).

    Google Scholar 

  15. Holder, C. D. The relationship between leaf hydrophobicity, water droplet retention, and leaf angle of common species in a semi-arid region of the western United States. Agric. Forest Meteorol. 152, 11–16 (2012).

    Article  Google Scholar 

  16. Glime, J. M. Bryophyte Ecology, Vol. 1: Physiological Ecology (Michigan Technological University and the International Association of Bryologists, 2007).

  17. Zheng, Y. et al. Directional water collection on wetted spider silk. Nature 463, 640–643 (2010).

    Article  CAS  Google Scholar 

  18. Martorell, C. & Ezcurra, E. The narrow-leaf syndrome: a functional and evolutionary approach to the form of fog-harvesting rosette plants. Oecologia 151, 561–573 (2007).

    Article  Google Scholar 

  19. Park, K.-C., Chhatre, S. S., Srinivasan, S., Cohen, R. E. & McKinley, G. H. Optimal design of permeable fiber network structures for fog harvesting. Langmuir 29, 13269–13277 (2013).

    Article  CAS  Google Scholar 

  20. Garland, J. Some fog droplet size distributions obtained by an impaction method. Q. J. R. Meteorol. Soc. 97, 483–494 (1971).

    Article  Google Scholar 

  21. Lorenceau, É. & Quéré, D. Drops on a conical wire. J. Fluid Mech. 510, 29–45 (2004).

    Article  Google Scholar 

  22. Li, E. Q. & Thoroddsen, S. T. The fastest drop climbing on a wet conical fibre. Phys. Fluids 25, 052105 (2013).

    Article  Google Scholar 

  23. Tokay, A., Petersen, W. A., Gatlin, P. & Wingo, M. Comparison of raindrop size distribution measurements by collocated disdrometers. J. Atmos. Ocean. Technol. 30, 1672–1690 (2013).

    Article  Google Scholar 

  24. Johansson, E., Bolton, K. & Ahlström, P. Simulations of vapor water clusters at vapor–liquid equilibrium. J. Chem. Phys. 123, 024504 (2005).

    Article  Google Scholar 

  25. Proctor, M. C. et al. Desiccation-tolerance in bryophytes a review. Bryologist 110, 595–621 (2007).

    Article  CAS  Google Scholar 

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We want to thank M. Standing for providing SEM/ESEM support, L. Allphin-Rapier for providing ideas and discussions, Z. Aanderud and his students for providing samples, A. Downing for proof reading and BYU internal support for Z.P. and the SEM/ESEM experiments. The work of Y.Z., N.W. and Y.T. were funded by the National Basic Research Program of China (2014CB954202).

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Authors and Affiliations



N.W. and Y.Z. originated the research on S. caninervis and provided anatomical studies, both macro and microscopic. Z.P., T.T.T. and W.G.P. designed the experiments, and Z.P. and T.T.T. performed the experiments and analysed the data. Z.P and W.G.P. proposed the mechanisms of nucleation on the moss awn. W.G.P., Z.P. and T.T.T. wrote the text.

Corresponding author

Correspondence to Tadd T. Truscott.

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The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Section ‘Dew nucleation and fog droplet collection in a groove’, Supplementary References, Supplementary Figs 1–3 and captions for Supplementary Videos 1–5. (PDF 1448 kb)

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Supplementary Video 1 (MP4 383 kb)

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Supplementary Video 2 (MP4 480 kb)

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Pan, Z., Pitt, W., Zhang, Y. et al. The upside-down water collection system of Syntrichia caninervis. Nature Plants 2, 16076 (2016).

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