  Using 'spatially' resolved spectroscopy, we investigated the characteristics
and different modes of formation of stars in elliptical galaxies. We identified
an unusual population of 59 star-forming elliptical (SF-E) galaxies in
SDSS-MaNGA, our primary sample. To identify these rare star-forming
ellipticals, we combined GSWLC-A2 containing outputs of stellar population
synthesis models with morphological results from the deep-learning catalog and
resolved and integrated properties from the MaNGA Pipe3D value-added catalog.
We have also constructed two control samples of star-forming spirals (SF-Sps;
2419 galaxies) and quenched ellipticals (Q-Es; 684 galaxies) to compare with
our primary sample of SF-Es. H$\alpha$ emission line flux of SF-Es is similar
to spiral galaxies. The D4000 spectral index indicates that SF-Es have a
mixture of old and young stellar populations. Mass-weighted stellar age and
metallicity for the SF-Es are lower than the Q-Es and 67\% of stellar- and gas-
velocity maps of the primary sample show signs of kinematic disturbance. All of
these indicate that SF-Es have acquired metal-poor gas through recent mergers
or interactions with other galaxies and are forming a new generation of stars.
Further, we subdivide our primary sample of SF-Es into four classes based on
their bulge to total luminosity ratio $(B/T)$ and spin parameter
$\lambda_{re}$. These four classes have their distinct evolutionary history and
modes of formation. Based on these results, we suggest that the Hubble diagram
does not accurately capture galaxy evolution processes, and we need a revised
morphology diagram like the comb morphology diagram to get a complete picture
of the galaxy evolution processes.
