As per efi thread:
I think the difference given in another post as below by … may be more appropriate to differentiate them as per POWO (Allamanda schottii Pohl) and POWO (Allamanda cathartica L.):
“A. cathartica, long cylindrical tube and much shorter swollen upper half is distinctive, in A. schottii cylindrical portion is much shorter than moderately swollen upper portion”
A. cathartica : A tropical twining vine with deeply veined, whorled leavesand large, trumpetshaped bright yellow flowers.
A. nerifolia (Syn. of Allamanda schottii Pohl): A bush typically grows to 4-5 ft tall. It bears clusters of yellow, trumpet-shaped flowers with orange-red throat stripes. Flowers are bell-shaped with a golden yellow corolla, striped orange at the throat.
Re: completed insertion of identified species of Allamanda : 1 post by 1 author
Allamanda page (Apocynaceae) with images of species in efloraofindia : 1 post by 1 author.
If you find any mis-identification, pl. let us know.