Greyish green with stomata on both surfaces of the leaf, 30 by 28μm, mostly
rubiaceous type. Palisade cells differentiated into 2 layers of cells, 45 by 25μm;
spongy parenchyma of about 3 layers of cells with many intercellular spaces,
some with crystals of calcium oxalate; midrib region shows 2 or 3 layers of
parenchymatous cells without chloroplastids; petiole shows epidermis with
thickened inner walls; collenchyma of 2 or 3 layers of cells; a broad zone of
parenchyma; 7 vascular bundles within parenchymatous zone, 2 in projecting
arms and 5 forming the central strand; vessels 15–23μm in diameter. Some
parenchymatous cells contain crystals of calcium oxalate. Fruits, epidermis of
polygonal cells, trichomes similar to the leaves, sheets of elongated parquetry
layer cells, bundles of narrow annular vessels, and parenchymatous cells contain
single large prisms of calcium oxalate (4).