ABUNDANCE

Species of Philodendron vary considerably in abundance. If juvenile plants and pre-adult plants are included, some species, such as P. sagittifolium, in areas of Tropical moist forest (T-mf) occur literally everywhere, growing over the surface of the ground and climbing on most trees of modest to large size. In another area it might be another species, such as P. radiatum, P. hederaceum, P. tenue or P. tripartitum, that is locally more abundant. In any moist habitat one does not have to search long to find some species and usually many species of Philodendron. Even species which are poorly known or known from only one area are generally quite abundant in the area where they occur. Thus is it particularly strange when one encounters a species, such as P. hammelii, P. folsomii, P. morii, or P. chirripoense, which do indeed appear to be rare, failing to turn up even in areas where they have previously been collected.

Although fecundity of seeds is high and early success is dependent on severe competion (since seeds are often deposited in large numbers where they fall), individual plants are mobile, growing in random directions initially while they develop roots and begin to take advantage of new nutrient sources. This ability to quickly cover a lot of distance with the development of long, slender internodes, is a part of their success and no doubt is why plants soon cover much of the area of the forest. Seedlings in general grow much more rapidly than those of Anthurium which are also more limited in generally having much shorter internodes and taking much more time to position themselves as trunk hemiepiphytes. The smaller but much more numerous seeds of Philodendron, coupled with generally rapid growth and usually scandent habit, explain why some species are so abundant.