Vein-endings, free vein-endings, isolated vein-endings and isolated tracheids are discussed and distinguished. Vein-endings whether simple or branched may or may not terminate in terminal tracheids. The nature of vein-endings is uniseriate inSolanum species while multiseriate inCestrum species. Tracheids at the vein-tips increase cell diameter and are variable in size, shape and orientation. Tracheids at junction of free arms of the veins are observed inWithania somnifera Isolated vein-endings, isolated free vein-endings and isolated tracheids are noticed inCestrum diurnum, C. nocturnum andSolanum surattense.

The structure and ontogeny of normal and abnormal stomata in the seedlings of 16 species of the Cruciferae have been presented. The mature stomata are anomocytic, paracytic, anisocytic, helicocytic and with a single subsidiary cell. The ontogeny of the anisocytic, paracytic, helicocytic and stoma with a single subsidiary cell conforms to the syndetocheilic or mesogenous, while that of anomocytic to haplocheilic or perigenous type. Several types of aberrant stomatal formations such as: single guard cell; contiguoas single-guard cells; contiguous stomatal; degeneration of guard cell/s; persistert stomatal cell; amitotic division of guard mother cell nucleus followed by pore formation; stoma with double pores; binucleate guard cell; division of guard cell; incomplete stoma with unequal guard cells; cytoplasmic connection; ring-shaped division of guard mother cell and uncommon wall thickening have been noticed. Aberrant stomatal developments are naturally occurring and not induced.

Leaf architecture including venation pattern has been studied in 19 genera and 29 species of the Apocynaceae. The leaves are simple, alternate, opposite or whorled with entire margin and a simple midrib. The major venation pattern conforms to pinnate camptodromous type with festooned brochidodromous secondaries. The qualitative and quantitative features are charted. The leaf size, areole size, number of vein endings entering the areoles and number of vein terminations entering the areoles vary from species to species even within the same species. The highest degree of vein order is observed up to 7°. Isolated tracheids, isolated vein endings, isolated free vein endings and tracheoidal elements are noticed. Bundle sheath cells ensheaths all category of veins.

Structure and development of stomata have been studied in 14 genera and 22 species of the Acanthaceae. The leaves ofNeuracanthus sphaerostachys are hypostomatic while those of other species investigated are amphistomatic. The stomata are typically diacytic, monocyclic or incompletely or completely amphicyclic being surrounded by 2,3 or 4 subsidiary cells and mesogenous in development having been formed as a result of three, four or five successive mitotic divisions of the meristemoid. Arrested developments, single guard cells with or without pore, contiguous stomata and aborted guard cells are the common abnormalities noticed.

Cotyledonary blade is symmetrical in all the species of Asteraceae. Morphological features such as base, apex and margin vary from species to species. Venation pattern conforms to pinnate craspedodromous, pinnate camptodromous and acrodromous type. Higher order veins noticed are up to 5°. Primary vein is either stout massive, moderate or weak. The thickness of the veins gradually decreases from primary to higher order veins. Marginal ultimate venation is either incomplete, looped or fimbriate. Areoles are absent inEclipta prostrata, Chrysanthemum segetum andCalendula suffruticosa spalgarbiensis. Vein endings are either simple or branched. In some species veins lack vein endings, which may or may not be associated with tracheids. Tracheids vary in their shape and arrangement in different species. Loop formation is observed. Isolated tracheids and extension cells are observed inCalendula suffruticosa sptomentosa. All categories of veins are jacketed by parenchymatous bundle sheath.

The extrafloral nectaries ofBignonia illicium occur on the foliage leaves, while the toral nectary is found on the torus around the ovary base. The extrafloral (foliar) nectary is non-vascularised and consists of a single layered secretory tissue followed by a large single celled stalk and single layered foot. The toral nectary is composed of isodiametric parenchymatous cells supplied with phloem. Symbiotic relationship between the animal visitors and the nectaries and their probable functions are discussed.

The pericarp ofHibiscus sabdariffa can be differentiated into epicarp, mesocarp and endocarp. The epicarpic cells are vacuolated, compressed and tangentially elongated. The mesocarp becomes 5–7 layered thick and the vacuolation and disorganization of its cells are simultaneous with the fruit development. Three to five layered endocarp at mature stage possesses sclereids and fibers of diverse shapes. The dehiscence ofHibiscus sabdariffa fruit is loculicidally columnicidal.

The organographic distribution, structure and ontogeny of non-articulated laticifers are studied inPlumeria alba. The distribution of laticifer branches is studied in stem, pedicel, petiole, lamina, petal, stamen, ovary, wall, style and stigma. Laticifer branches are observed in all except anther lobes and stigma. The wall of the laticifers is thicker than in the other cells and the cytoplasm contains many nuclei. Round starch grains were found in the neighbouring parenchyma cells, but starch grains are lacking in the laticifers. The laticifer branch can occur on either side of procambium of the shoot and these cells can easily be distinguished from other cells by larger size, prominent nuclei and denser cytoplasm. Laticifers grow intrusively along the intercellular spaces.

In some Apocynaceae a group of 10–15 resin glands is present as finger-like projections on the adaxial side of the proximal end of the petioles and sepals or petals. They originate from a group of epidermal and sub-epidermal cells. At maturity the glands are differentiated into a short stalk and a clavate head. The latter is composed of epidermal secretory cells and sub-epidermal parenchyma. Structurally and ontogenetically the resin glands resemble extrafloral nectaries and the standard colleters of the Rubiaceae. However, histochemical tests for lipophilic substances revealed that these glands secrete resin. The pale yellow, viscous secretion is released by cuticular bursting and covers the tender shoot apices and developing buds. The position and the secretory activity of the resin glands in relation to their function is discussed.

The pericarp ofAbelmoschus esculentus is differentiated into 3 distinct zones—the epicarp, mesocarp and endocarp. The epicarp is a product of outer epidermis and hypodermal parenchyma of the ovary wall. The growth of epicarp results from increase in the volume of cells of the periphery below the outer epidermis. In a mature pericarp the epicarpic cells become enlarged, vacuolated, thick walled and resemble collenchyma. The parenchymatous mesocarp is derived from the inner zone of ground parenchyma of the ovary wall. The large and vacuolated parenchyma of the developing mesocarp appear disorganised at maturation of the fruit. An interwoven pattern of endocarp is composed of sclerenchyma and develops from the inner epidermis together with inner sub-epidermis of the ovary wall. The dehiscence of ripe capsule ofAbelmoschus esculentus is the result of differentiation of mechanically weak cells in the median plane of each carpel, as well as in the central column and porus endocarp.

Effect of cement kiln dust pollution on black gram (Vigna mungo) has been studied by comparing plants of polluted as well as from non-polluted areas. Due to cement kiln dust accumulation on exposed parts of the plant, there was a decrease in height, phytomass, net primary productivity and chlorophyll content. Quantitative estimations and histo-chemical localization indicate lowering of metabolites in dusted plants as compared to control one. In polluted plants, damaged leaves show increase in stomatal index and trichome frequency and decrease in stomatal frequency. Cement kiln dust accumulation on plant surface showed decrease in the number and size of flowers which finally affected the yield to a great extent in the dusted plants.