Monographs Details: Mapania humilis Nav.-Ros. & Vill
Authority: Koyama, Tetsuo M. 1966. The systematic significance of leaf structure in the Cyperaceae-Mapanieae. Mem. New York Bot. Gard. 15: 136-159.
Description:Species Description - Leaf blades inconspicously inversely W-shaped, with vascular bundles at both lateral costas slightly different in structure from other lateral vascular bundles. Epidermis. Adaxial epidermal cells tall, nearly square. Hypodermis absent except at median adaxial surface. Swollen translucent tissue at median adaxial surface 3- or in part 4-layered, the component cells longitudinally rectangular or almost square in epidermal layer. Abaxial epidermis of relatively tall cells. Mesophyll more or less divided by vascular bundles and accompanying mechanical tissue, each section of mesophyll consisting of palisade chlorenchyma, spongy chlorenchyma and translucent tissue; translucent mesophyll occupying most part, the component cells large, mostly transversely oval, extremely thin-walled; palisade chlorenchyma 2 or in part 3-layered, with scattered round or oval translucent cells, the assimilatory cells longitudinally rectangular in adaxial layer, or transversely oblong in inner layer(s); spongy chlorenchyma 2- or 1-layered, with scattered translucent cells, the component cells transversely oblong to transversely linear. Vascular bundles of varying size arranged in a single row, the larger bundles oval in outline, the small ones tending to be orbicular in outline; bundle sheaths double, the inner sheath of sclerified cells complete, the outer sheath of thin-walled translucent cells interrupted abaxially by vascular sclerenchyma; phloem well developed. Vascular bundles at both lateral costas (Fig. 20) elliptic in outline, the outer bundle sheath expanding into adaxial thickening (Fig. 20, t), the inner sheath discontinuous adaxially. Sclerenchyma. Median costal vascular bundle supported by an adaxial cap and an abaxial deeply crescentiform girder. \ ascular bundles at lateral costas with an adaxial shallowly lunate girder and an abaxial deeply crescentiform girder with extended margins covering the abaxial half of the bundle. Other lateral vascular bundles with an adaxial fiber strand and an abaxial low-I-shaped girder (Fig. 22). All girders and vascular bundles accompanied by oval translucent cells.
Note. The translucent cells adjoining the vascular sclerenchyma and the fibrovascular systems are definitely smaller than those of the translucent meso-phyll, and their cell walls are somewhat thicker than those of the latter.