Ipomoea coccinea L., Sp. pl. 1:160. 1753 (Syn: (≡) Quamoclit coccinea (L.) Moench) as per GRIN?; 
Ipomoea hederifolia has erect fruit
The most important feature to capture for Ipomoea hederifolia to differentiate from Ipomoea coccinea is the calyx of the fruit in various stages…
The leaves on both Ipomoea hederifolia and Ipomoea coccinea can mimic each other (I know because I have grown enough of them myself) but the pedicels of Ipomoea hederifolia always remain erect while the pedicels of Ipomoea coccinea reflex…
So, in my experience trying to differentiate Ipomoea hederifolia from Ipomoea coccinea using any other part except the calyx and pedicel will lead you astray…

Convolvulaceae Week_Ipomoea rubriflora 01_RKC16032012: Back to work after long vacation. Learnt about the changing Google policies and decided to post my fotos on flickr. Posting a few images of Ipomoea rubriflora O’Donell as a test mail. Hoping to share more in future.

I’ve noticed the entry for Ipomoea coccinea here :
my strong position is that the plant List is once again, very wrong.
I have repeatedly warned about the Plant List and many innacuuracies and this is an outstanding one.
Ipomoea coccinea is still recognized by the ars-grin site and the Kew database.
Ipomoea coccinea
WCSP science
Ipomoea rubriflora
WCSP science
The treatment describing Ipomoea rubriflora is in “Ipomoea of Bolivia” where it is described as :
1) rare
2) occurring in only a very small locality in Bolivia and no where else
So, the Plant List is Wrong.
Ipomoea coccinea should in no way, shape, manner or form be confused with Ipomoea rubriflora.
Should you decide to update the reference, please change the url to contain Ipomoea coccinea instead of Ipomoea rubrifloa to help prevent any confusion.
Please always double check whatever the Plant List states by cross referencing both ars-grin and the Kew database.

Should we keep this entry at all when there is hardly any noticeable difference between this & Ipomoea hederifolia ?

Now I am wondering if the ones I have labelled as Ipomoea heredifolia are correct or not.

I’m not entirely certain of which entry you want to dispose of…
Regarding the following:
1) Ipomoea rubriflora occurs only in Bolivia and is quite unlikely to occur in India, so if the listing for Ipomoea should reflect only those likely to occur in India, then it may not be indicated, although, to keep the taxonomy clear, you might want to retain the I.rubrifloa and if you need it here is the reference :
Ipomoea (Convolvulaceae) in Bolivia, Kew Bulletin (2015) 70:30.Wood1,2, M. A. Carine3, D. Harris4, P. Wilkin2, B. Williams1 & R. W. Scotland1
2) Ipomoea coccinea has reflexed fruit and only 28 chromosomes and is recognized by both ars-grin and Kew as a distinct species.
I believe this should have it’s own devoted entry
The photo on the left currently in this entry has clearly erect fruit and is Ipomoea hederifolia, while the photo on the right has no fruit and cannot at this stage be distinguished as Ipomoea hederifolia or Ipomoea coccinea.
3) Ipomoea hederifolia has erect fruit, 30 chromosomes and is chemotaxonomically different than Ipomoea coccinea.
I believe Ipomoea hederifolia should have it’s own devoted entry.
There has been much confusion over distinguishing Ipomoea coccinea from Ipomoea hederifolia mainly because people don’t know what to look for and erroneous guides also based upon mis-identification and confusion, although I believe the aspect to observe the behavior of the pedicel in fruit is the easiest way of differentiating between the 2 different species.
I think your site should help to eliminate confusion by providing distinguishing details, rather than simply glossing  over historically confused areas.
I can only share my opinion, you are the administrator and I respect your right to construct the site as you see most befitting.
Thank you for the opportunity to comment on this area.
P.S. – Please share any aspect of my communications with you as you see befitting.
I tried to login a few days ago and google didn’t like the email I provided, so I was unable to login…I’ll try to get this rectified at some point…