3. P. subsect. Oligocarpidium
Engl., Bot. Jahr. 26.
LectoTYPE: P. multispadiceum Engl. (designated by Mayo, 1989).
As defined by Krause, the group was very heterogenous. Though he treated only four species, they differ greatly from one another. Philodendron deviatum Schott (now a synonym of P. jacquinii) was placed by Krause in its own P. sect. Macrogynium . Another of the species that he included, P. pittieri, is just poorly preserved material of P. hederaceum which Krause placed in his P. `Gruppe' Solenosterigma in P. sect. Philodendron. This leaves only P. multispadiceum and P. muricatum, which in my opinion are quite unrelated. Philodendron muricatum is the oldest name for two other synonyms, P. jenmanii K. Krause and P. scabrum which were placed in P. subg. Solenosterigma. Though I am doubtful of the affinity between P. hederaceum and P. muricatum it seems best to include it there because P. muricatum is clearly a member of P. sect. Philodendron and not P. sect. Calostigma.
This leaves only P. multispadiceum, which fortunately Mayo (1990) chose as the type. There are two Central American representative of the subsection and a number of other undescribed South American species as well. Central American species are P. clewelii and P. heleniae.
The subsection is distinguished by having a relatively large number of small (usually 4-10 cm long) inflorescences per axil. Plants are vines with long internodes and long-petiolate, narrowly ovate to ovate-cordate blades which have the basal veins either lacking or all free to the base and without the development of a posterior rib. Both Central American species represented have a type B style and an ovule sac surrounding the ovules.