Robert D. Warmbrodt, Structure of the Leaf of Pyrossia longifolia -- A Fern Exhibiting Crassulacean Acid Metabolism, American Journal of Botany, Vol. 71, No. 3 (Mar., 1984), pp. 330-347 ...

A hypothesis that a dense stand should develop a less uniform distribution of leaf nitrogen through the canopy than an open stand to increase total canopy photosynthesis was tested with experimentally ...