I am not too sure but this may not turn out to be Catalpa bignonioides. Perhaps Satish ji can recollect and apply this key more accurately:
C. bignonioides C. speciosa
Leaves 12-20 cm long, ill smelling when bruised Leaves 15-30 cm long, odorless, long acuminate
Flowers in broadly pyramidal 20-25 cm long panicles Flowers in few-fld 15 cm long panicles
Flowers white with two yellow stripes and thick Flowers white, inconspicuously spotted inside, lobes spreading
purple-brown spots. with frilled margin
Pod about 6 mm thick Pods 12-20 mm thick.
Here are some links for C. speciosa
And some for C. bignonioides
Interestingly C. ovata (Chinese or Eastern Catalpa) and C. bignonioides (Common catalpa, Indian bean) are two far separated species that show the phenomenon of Viccariance. For those interested more, here is information from my book.
The phenomenon of disjunction in some genera may often result in two very closely related species of a genus occupying different geographical regions, so that under natural conditions they would never meet. Classical example is provided by two species of Platanus, P. orientalis growing in Mediterranean region and P. occidentalis of North America. The species are quite distinct in vegetative and floral morphology and have long been treated as distinct species without doubts ever being raised. In places, however, when specimens of these species were grown together, they readily interbred, producing hybrids, which were not only fertile, but also intermediate between them. Obviously extended geographical isolation had developed morphological differences, but no reproductive barriers. Such closely related species growing in different geographical regions constitute vicariants or vicariads, and the phenomenon as vicariism or vicariance. Another significant example is met in the genus Catalpa, C. ovata growing in China and Japan, and C. bignonioides growing in North America. Other examples include Viola cazorlensis of Spain and V. delphinantha of Greece, Convolvulus lanuginosus of France and Spain and C. calvertii from Crimea and S. W. Asia. Vicariance may often involve more than two species as in genus Cedrus, C. atlantica of Atlas mountains of Morocco, C. brevifolia of Cyprus, C. libani of Lebanon, Syria and Turkey, and C. deodara of the western Himalayas, all well separated geographical regions.
Vicariance may evolve in a number of ways. A taxon may migrate to a new area and evolve into a new taxon there. A formerly widely continuously distributed taxon may, similarly, become separated into different areas and there undergo divergent evolution. There may also be parallel evolution of two taxa from common ancestor in two different areas. Theoretically this may also result from convergent evolution under similar environmental conditions, but this false vicariance, which may result from superficial resemblance, can be easily detected and rejected.
The phenomenon of disjunction and vicariance has received renewed interest in the recent years with the utilization of principles and techniques of cladistic analysis in the studies of distribution patterns, resulting in the establishment of field of cladistic biogeography or vicariance biogeography. Using this method, cladograms of taxa are constructed, and the names of the taxa at branch ends are substituted by the areas of their distribution, forming so-called area-cladograms. A pattern can be repeatedly constructed using different groups of organisms, and compared for true representation of relative origins of floras (or faunas) of the areas concerned. The area-cladograms can be represented on a map, and areas linked with lines called tracks. The procedures have generated lot of interest with clearer ideas about continental drift and better understanding of the concept of plate tectonics.
Dr. Gurcharan Singh
Retired Associate Professor
SGTB Khalsa College, University of Delhi, Delhi-110007
Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018.
Phone: 011-25518297 Mob: 9810359089