COLLECTING HISTORY OF PHILODENDRON SUBG. PHILODENDRON
In addition to the history of revisionary efforts it is instructive to consider the collecting efforts in Central America that has laid the groundwork for the scientific work done with Philodendron subg. Philodendron. Perhaps owing to their sometimes intimidating size, the difficulty of retrieval and certainly due to the difficultly of preparing and drying specimens, members of P. subg. Philodendron have never been popular with botanical collectors beginning even with the earlier collectors. The early neotropical collectors, i.e., Ruiz and Pavon, Sesse and Mocino, Triana and Planchon and others collected few Araceae (or at least few survived to modern times). Eduard Poeppig, working in Peru, and Richard Spruce, working in the Amazon region of Brazil, did somewhat better, collecting a number of new species of Araceae. In Central America few collectors made many collections until modern times. Even Paul C. Standley and Julian A. Steyermark, two of the most prodigeous collectors in the region did not make many collections of Araceae. Both collected well over 100,000 collections in their careers. Yet in all Standley made only 146 collections of P. subg. Philodendron, comprising only 21 species in all of Central America (including Panama). Of this total only five of the collections proved to be new species, none of which Standley recognized as new. The new species he collected were: P. crassispathum, P. findens, P. purulhaense, P. verapazense, and P. wilburii Croat & Grayum var. wilburii. Standley was not avoiding collecting Philodendron because they constituted a lot of work to press. This is demonstrated by the fact that he collected P. radiatum 13 times and P. warszewiczii 12 times. These are among the most difficult plants to prepare owing to their huge size and fleshy parts.
That so few new species of Philodendron were collected was apparently due to the fact that in earlier times relatively few roads led into areas of wet forest.
Matuda, working exclusively in Mexico and concentrating on Araceae, collected only 27 collections of P. subg. Philodendron and only one of these, P. glanduliferum, proved ultimately to be new to science. George Bunting, also collecting only in Mexico (under collecting numbers of Harold Moore of Cornell University), made 36 collections of P. subg. Philodendron, including two new species (P. dressleri and P. jodavisianum).
Steyermark, though collecting many more Philodendron in Venezuela later in his career, collected only 26 Central American P. subg. Philodendron, comprising a total of nine species, none of which were new. Louis O. Williams who also worked on the Flora of Guatemala and who collected for many years in Guatemala, Honduras and Costa Rica, made only 14 collections of P. subg. Philodendron. Two of these were species that remained undescribed until this work, namely Williams 628 (P. sulcicaule) and Williams 28387 (P. wilburii Croat & Grayum var. longipedunculatum Croat & Grayum). Percy Gentle, collecting in Belize made 20 collections. The Philodendron subg. Philodendron collections of Pittier in Costa Rica totaled only 9 with only two (4015 and 4398) representing a new species (P. pseudoauriculatum Croat). Adolfe Tonduz, also working in Costa Rica made only five collections of this group. Albert Brenes made four collections in Costa Rica between 1926 and 1932. Two of them P. brenesii and P. bakeri Croat & Grayum proved to be new. Paul Allen made five collections of Philodendron in Costa Rica, four of which were described as new (though two were subsequently synonymized). Aside from these few collections of new species mentioned above no other new species were collected until the early 1960s. Roy Lent, living in Costa Rica and collecting between 1964 and 1971, made 24 collections of P. subg. Philodendon including five new taxa. These included: P. lentii Croat & Grayum, P. scandens var. kirkbridei, P. strictum, P. thalassicum Croat & Grayum, P. wilburii var. wilburii. W. C. Burger, collecting in Costa Rica between 1968 and 1986, in part with one time aroid specialist Richard Baker, made 56 collections of P. subg. Philodendron including five new species, P. bakeri, P. chirripoense, P. crassispathum, P. thalassicum, and P. wilburii.
Collecting activity in Panama, despite being even richer than Costa Rica was not particularly rewarding. The collections of H. von Wedel, who collected in Bocas del Toro Province in Panama totalled only seven. Robert Woodson and his collaborators, Paul Allen, and Carrol Dodge collectively made only 11 collections before the Flora of Panama project was begun. This, in a country which proved to have 96 species, 65 of which were new to science.
Even collectors like James Duke, who regularly got into areas of wetter forest in many parts of Panama, collected only four collections of P. subg. Philodendron, none of them new.
Collecting activities begun by Walter H. Lewis and staff from the Missouri Botanical Garden in the early 1960's were more aggressive, had U.S. Air Force support and, by using helicopters, got into areas not previously accessible. Despite this greater penetration, even these expeditions resulted in few specimens of Philodendron. John Dwyer, one of the principal participants in these early expeditions, made 14 collections of Philodendron (mostly from Panama), two of which (P. dwyeri (from Belize) and P. straminicaule Croat) were new to science. During the same period, Edwin Tyson, while teaching for Florida State University in the former Canal Zone, made 16 collections, five of them new to science. These included: P. annulatum Croat, P. dolichophyllum Croat, P. lazorii Croat, P. llanoense Croat, P. tysonii Croat. Even the late Alwyn Gentry, who made more than 80,000 collections of tropical American plants during his career and who went to many remote and interesting areas, made only 24 collections of P. subg. Philodendron in Central American. Three of them, P. llanoense Croat, P. pseudoauriculatum, and P. wilburii were undescribed at the time.
Collecting in Honduras, Costa Rica and Panama between 1973 and 1993, Ron Liesner collected 43 species of P. subg. Philodendron, four of them, P. alticola Croat & Grayum, P. crassispathum, P. findens, and P. llanoense, new to science.
Michael Grayum, an aroid specialist working primarily with P. subg. Pteromischum, was involved personally or in conjunction with other collectors, in collecting (since 1984) a total of 426 Philodendron (in both Central and South America) of which 153 of his 205 personal collections, were P. subg. Philodendron for Central America. Being a specialist, his collections are particularly useful, since they are accompanied by excellent field notes. He was responsible for collecting 13 undescribed species of P. subg. Philodendron, including: P. angustilobum Crpat & Grayum, P. aromaticum Croat & Grayum, P. bakeri, P. brunneicaule Croat & Grayum, P. cotobrusense, P. crassispathum, P. cretosum Croat & Grayum, P. dodsonii Croat & Grayum, P. grayumii Croat, P. scalarinerve Croat & Grayum, P. straminicaule, P. thalassicum, and P. wilburii.
My own collecting activities with Philodendron began in 1967 with work on the Flora of Barro Colorado Island. Collecting on BCI and taking other trips in Panama with Walter Lewis, John Dwyer and others gave me my first real experience collecting Araceae. Many of the areas visited were areas not previously collected in wet or very wet areas where numerous new Araceae occurred. Many species were collected for the first time even in areas where considerable collecting had been carried out in the past. In some cases nearly all the species collected on a given day proved to be new to science. Later when serving as the Missouri Botanical Garden's resident botanist in Panama, during 1970-1971, and while continuing my work on Barro Colorado Island, I took many field trips to other areas of Panama. By this time I had become seriously interested in collecting Araceae and many plants were brought back to Summit Garden for cultivation and study. Upon my return to St. Louis, most of these collections were shipped to the Missouri Botanical Garden where many have persisted. In all 3,582 collections of Philodendron have been by myself (or sometimes in conjunction with another collector) in Central and South America, 1715 of these were made in Central American and 1594 of this total were members of P. subg. Philodendron. In all, these Central American collections represented 52 undescribed species.