Anatomy of hydathodes and pigment disks in leaves of Ficus diversifolia (Moraceae)

In Ficus diversifolia , "mistletoe fig", hydathodes are scattered over the leaf lamina. They open to the adaxial surface via a circular, slightly depressed epidermal pad studded with 20–30 water pores. The epithem is a cylinder of small cells, irregular in shape, with conspicuous intercellular spaces, bounded by a close-fitting sheath of unpigmented cells. Hydathodes occur above characteristic junctions of three or more minor veins, from which short tracheary strands extend upward into the epithem and end blindly. Phloem does not seem to be involved. Unsuccessful attempts were made to induce guttation. Red pigment spots occur abaxially in the axils of major veins. They are compact internal disks of parenchyma cells containing granules of various sizes. A vascular bundle arches downward, passes over the disk, then curves upward to rejoin other bundles. The central large disk has a palisade epidermis of slender elongate cells separated from each other by cuticle; the other disks have a normal epidermis.     

Crystals in tapetal cells of the Leguminosae

In a survey of the Leguminosae (167 species of 89 genera), calcium oxalate crystals were found in tapetal cells in all three subfamilies (84 species of 52 genera). Crystal form ranged from small scattered crystals to lens-like to various large prismatic types, and included the first report of styloid crystals in the Caesalpinioideae. Over half of the caesalpinioid and papilionoid legumes examined had crystals. Crystals were not common in the Mimosoideae, however, but this may be because of the small sample. The distribution of species with various crystal types, and of species lacking crystals, did not reveal any patterns that conform to the presently defined taxa. Crystals in tapetal cells have previously been reported only in the Commelinaceae and Labiatae.