Development of seed and fruit in Bischofia javanica Blume (Phyllanthaceae)

Development of seed and fruit in Bischofia javanica Blume (Phyllanthaceae)

Taxonomic affinity of genus Bischofia needs to be reaffirmed in view of the splitting of the erstwhile Euphorbiaceae into six distinct families. In addition, the role of the reproductive features in reported invasive nature of the tree species Bischofia javanica also requires to be investigated. To answer these questions, reproduction and fruit/ seed development have been investigated in, Bischofia javanica Blume (Phyllanthaceae). All stages of flowering and fruit/ seed development were collected, fixed in formalin-acetic-alcohol, sectioned with rotary microtome and stained with safranin-astra blue for study with light microscope. The ovule is anatropous, bitegmic and crassinucellate. Distinct obturator and hypostase are present. Embryo sac development is of Polygonum type. Pollination is anemophilous. Development of endosperm is of nuclear type. The embryogeny conforms to the Capsella variation of the onagrad type. At the organized embryo sac stage, the outer as well as the inner integument consist of three or four layers of cells. Seed is exotegmic. As the pericarp matures, the inner subdermal cells become sclerosed, acquire prismatic crystals and constitute the stony endocarp. Cells of the middle zone enlarge considerably and several trichosclereids are also differentiated. The exocarp is smooth and tanniniferous. Fruit is a 3-loculed, loculicidal capsule or schizocarp. Based on the embryological features, placement of Bischofia in the family Phyllanthaceae is justified. Profuse flowering, anemophily, high rate of fruit/seed set, extended seed viability and ability of seedling to grow well in shade or light are among reproductive features that can aid invasive behaviour of the species.