Argyreia bella ?

Argyreia bella (C. B. Cl.) Raiz. (syn: Convolvulus vestitus Wall.; Lettsomia bella C. B. Cl.; Mouroucoa bella (C. B. Cl.) Kuntze) ?;

India, Nepal as per Catalogue of Life;
SK 2282 08 November 2019 : 18 posts by 4 authors. Attachments (3) - 2 mb each.
Location:  Ranimahal, Palpa
Date: 25 September 2019
Elevation:648 m.
Habit : Wild
Which Argyreia ? Central part of flower is not dark compared to images in Net!

Attachments (2) - 2 & 3 mb. 

Attachments (2) - 2 & 3 mb. 

Attachments (1) - 7 mb.

a. splendens  usually is light colored neck but leaves are very different. so I don't know what this one is
Argyreia nervosa (Burm.f.) Bojer ??
No, sir, not A.nervosa. Flower size ? It seems small.
Flower size is not rally small. Average to normal Ipomoea flower size.
In that case please check for Argyreia capitiformis
It is not listed ...!
I know, sir. I was checking all species listed. 
Among the listed ones, Argyreia bella suits most considering the leaf and inflorescence and flower. 
Problem is, there are not enough authentic live photos. Herbarium photos are not good enough for id the way we are doing here. 
Argyreia is difficult. 
Elevation is matching but not much images in the net and description for comparison. However, GBIF link looks matching, specially the flower cluster of the herbarium. Another aspect is that the central part does not
have dark colour compared to other sp.
I am no not fully convinced with id as Argyreia bella as per GBI specimens as leaf secondary veins look less and calyx and bracts also look somewhat different.
I am marking a copy to the author of Lectotypification of Argyreia bella (Convolvulaceae), in case he/ she helps us in the matter.
I am also not able to find description on the net.
i have gone thru this exercise with you all. i cant find any more than what you folks have. Does not BSI have a monogrpah on A.
Tragedy is, this species Argyreia bella was collected by Clarke from erstwhile Chhotanagpur, now Jharkhand and around  ... but I am yet to see any Argyreia bella post from that region on facebook

Ok, thanks. picture of that lectotype collected dated 1873. the leaves are still grey green ? how is that possible