Introduction place”. In the biological context a

Introduction

 

The
Oxford dictionary defines the word Population as “All the inhabitants of a particular place”. In the biological context a group of organisms
belonging to the same species and occupying a specified area comprises a
population. The individual in a population usually displays a great extent of
both genetic and phenotypic variability. The phenotypic variation observed is
the outcome of the amalgamation of both ecological factors and genetic
differences. Thus, there is a need to study how a population behaves in the
ecological framework; which is conducted in the field of Population Ecology.

 

 In this dissertation,
the population dynamics of Oxalis
corniculata L. has been studied in and around Delhi University, New Delhi
at three sites with emphasis on seed dispersal.

 

Taxonomy

 

The family Oxalidaceae belongs to Oxalidales. Oxalidales, Celastrales and Malphigiales are the
COM clade and is placed in the clade Fabids of Rosids(APG IV
classification,2016). Huaceae, Connaraceae, Oxalidaceae, Cunoniaceae,
Elaeocarpaceae, Cephalotaceae, Brunelliaceae are the seven families in
Oxalidales.

Oxalidaceae commonly known as the
wood sorrel family consists of 5 genus and a few hundred species. The type
genus Oxalis comprise of around 300
to 400 species most of which are herbaceous. The only exception is Oxalis gigantea, which has a shrub
habit. Majority of the
species are from the Southern Hemisphere, typically native to South America and
South Africa.

Characteristics common to all members of Oxalis are the presence of aboveground herbaceous stems; absence of
bulbs; trifoliate leaves, the leaflets all sessile, wider than long, and either
obcordate, bifid, or obdeltoid with a slight apical notch; homo- or
heterostylous flowers, usually yellow. Linnaeus first named and described Oxalis in his book Species Plantraum
published in 1753.

Among the many species of Oxalis present, O. corniculata is indigenous to Asia. It is found in relatively
undisturbed habitats and has evolved a series of local forms in moist tropical
Asia, Malaysia, Australasia, and some high islands of the Western Pacific. It
most possibly arose in this general region.  

It is the one species of the
genus Oxalis present in almost all
the conditions of moisture, light, temperature and soil that the other species
collectively endure. Therefore, either individuals of O.corniculata are phenotypically very tolerant, or, more probably,
the species has developed a series of discrete or clinally varying ecological
genetic races (i.e., ecotypes and ecoclines)

The characters most important in distinguishing taxa within the
genus are, primarily, the type, frequency, orientation and distribution of
hairs on the external parts of the plant, and secondarily, degree of
heterostyly, habit, inflorescence type, flower color, seed marking and number
per locule, and sizes of parts.