|Red List Category & Criteria:
||Freire-Fierro, A. & Pitman, N.
||Valencia, R., Pitman, N., Léon-Yánez, S. & Jørgensen, P.M. (Ecuador Plants Red List Authority)
A vine or liana endemic to Ecuador's southern Andes, where it is known from three subpopulations. The first was discovered near Portovelo before 1920. The second was collected in 1950 on the other side of the Andes, in an undetermined locale of Morona-Santiago province. The third was collected in 1993 on the Cordillera del Cóndor. Not confirmed to occur inside Ecuador’s protected areas network, but the third subpopulation may extend inside the recently created Parque El Cóndor. Portovelo's forests have been destroyed since the type collection, making S. leiocarpa Vulnerable due to a geographical range potentially confined to Morona-Santiago and Zamora-Chinchipe provinces. Apart from habitat destruction, no specific threats are known.