The ethnomedical use of Ipomoea spp leaves and powdered root is known. The applied species, however, are not the ones you grow in your garden as a so-called ornamental. Furthermore, its use as a herbal medicine in some regions of the world does not automatically imply that the leaves (or roots) contain LSA (and structurally related) substances. For as far as I and you know, the active components might be completely different (although wishful thinking is always allowed).
Those looking for basic information on morning glories, don't forget the Erowid website! (http://www.erowid.org)
(http://www.erowid.org) For more information, the following articles might be of interest as well:
- A Hofmann. Die Wirkstoffe der mexikanischen Zauberdroge Ololiuqui. Planta Medica 9 (1961) 354.
- JM Chao, AH Der Marderosian. Ergoline alkaloidal constituents of Hawaiian Baby Wood Rose, Argyreia nervosa (Burm. f.) Bojer. J Pharm Sci 62(4) (1973) 588
- K Genest. A direct densitometric method on thin-layer plates for the determination of lysergic acid amide, isolysergic acid amide and clavine alkaloids in morning glory seeds. J Chrom 19 (1965) 531.
- CG Santesson. Piule, eine mexikanische Rauschdroge. Arch Pharm (1937) 532 (interesting from a historical POV only).
- WA Taber, LC Vining, RA Heacock. Clavine and lysergic acid alkaloids in varieties of morning glory. Phytochemistry 2 (1963) 65.
- WA Taber, RA Heacock, ME Mahon. Ergot-type alkaloids in vegetative tissue of Rivea corymbosa (L.) Hall. f. Phytochemistry 2 (1963) 99.
The last article might support the idea that there are ergot-type alkaloids present in parts other then the seeds, but as you read the title, you have to take into consideration that the article only concerns a study of Rivea corymbosa, which is not the same as the more popular ornamental morning glory species.