These practices were geared toward moving foreign manufactures to the Americas, in return for gold and silver. However, a resident testaferro could in theory set up a rubber collection program on behalf of a USE customer. The catch, of course, is that there could be no direct supervision by a non-Spaniard.
Mexico, at least, has some degree of native trade in rubber, probably of Yucatan origin. In the sixteenth century, the Aztecs and Maya used it in making footgear, headgear, game balls, and incense (Shidrowitz, 2-5, 372-3). Hence, a local agent could put the word out that he was interested in rubber products, and expect to see some results. The rubber would have to be shipped overland or by "coaster" to Veracruz.
Of course, dealing with testaferros—not to mention Spanish officials—is going to cut into your profit margins, and it is conceivable that, once they recognize the military importance of rubber, the Spanish government will take pains to prevent the transfer of rubber from Spain to the USE. (Although Spain and the Netherlands happily traded with each other even while Spain was trying to reconquer the latter, and the special taxes which they imposed on trade with the enemy helped finance the war.)
You have the option of ignoring Spanish law and dealing directly with the Indians (or collecting the rubber yourself). If you are caught, you will likely to be tortured and put to death. So, my advice is, don't get caught.
The secret to success is to travel, preferably in fast, well-armed ships, to areas where the Spanish are weak, and where the natives, if any, are hostile to them.
One such area is the eastern half of the Yucatan peninsula.
Some of the Yucatec Maya have been in a state of revolt since 1610. Moreover, an independent Mayan state still exists in northern Guatemala (it wasn't conquered until 1697).
The southeast portion of the Yucatan is essentially uninhabited. Beginning in 1638, it was infiltrated by British logwood cutters. The Spanish attempted to expel the intruders, but in general were not successful, and the region ultimately became British Honduras (Belize).
Another weak point is the Meskito (Mosquito) Coast of Nicaragua. There are no significant Spanish towns or forts in-between Trujillo (Honduras) and the mouth of the San Juan River (which divides Nicaragua from Costa Rica). In fact, in our timeline, the English established a settlement at Cape Gracias a Dios in 1633, and went on to establish an informal alliance with the local Meskito Indians which endured for two centuries. (Perez-Brignoli, 13, 37, 53; Burns, 209, 362-5)
The USE could collect rubber from the Castilla trees in the Yucatan, British Honduras, northern Guatemala, Nicaragua and eastern Honduras. The Indians can be taught how to tap the rubber, and then we can visit them periodically to collect the material. If hostile forces compel us to engage in a quick in-and-out operation, we fell the trees and save seed for replanting in a more secure locale. We can increase our security by allying with the English Puritans on Providencia Island (about 150 miles off the coast of Nicaragua), and by capturing Jamaica (taken by the English in 1655). (Burns, 202-211)
The latex-producing properties of Castilla lend themselves to hit-and-run operations. A single tree can yield a great deal of latex at one tapping, but it can only be tapped one to three times a year. The specialist literature reports that Mexican bandits could steal a half-year's yield in a night, by surreptitious tapping. (Polhamus, 262)
* * *
While the Castilla tree is the oldest source of natural rubber, the Para Rubber Tree is the most important commercially. How readily can it be exploited by USE entrepreneurs?
Consulting an atlas, you will see that Para is the name of the province in Brazil which includes the mouths of the Amazon. There is also a map in CE which shows sources of wild rubber in South America. If we compare it with a physical map of the continent, it appears that the best places to look are along the banks of the Amazon proper, as well as near certain tributary rivers: the Rio Negro, Japura, Ica, Putumayo, Jurua, Madeira, and Tapajos. (Some of these may actually be sources of other kinds of wild rubber.)
The difficulties of navigating these waterways is discussed in the EB11 "Amazon" entry, which also calls our attention to "the great india-rubber districts of the Mayutata and lower Beni . . ." It additionally mentions that nineteenth-century rubber traders plied the Negro, the Madeira, and the Purus, that the "finest quality of india-rubber comes from the Acre and Beni districts of Bolivia, especially from the valley of the Acre (or Aquiry) branch of the river Purus," and that 35% of the Amazon Basin rubber is from the province of Para. The rest, presumably, is from the province of Amazonas.
The hazards of this venture are more political than navigational. The Treaty of Tordesillas (1494) sought to avoid conflict between Spain and Portugal in pagan territory, giving most of the Americas to Spain, and reserving Africa, Asia and northeastern Brazil to Portugal. The treaty actually gave the Amazon region to Spain. However, in 1580, the main royal line of Portugal came to an end, and Philip II of Spain became king of Portugal. In consequence, the Spanish rulers allowed the provincial authorities in Lisbon to take responsibility for policing the mouth of the Amazon.
In the late sixteenth century, the Portuguese were preoccupied with northeast Brazil, and the Spanish with Peru and Mexico, permitting the French, Dutch, English and Irish to establish settlements in the lower Amazon (the Dutch at the mouth of the Xingu river, and the English as far as 300 miles upriver). However, in the early seventeenth century, the Portuguese reacted violently to these incursions. They began by establishing the town of Belem, just south of the Amazon, in 1615. Then, during the period 1623-25, they sallied out and destroyed all of the non-Iberian holdings. Even the Catholic intruders were massacred. (Furneaux, 49-51; Smith, 141-2)
A logical question is, why not just send traders to Belem? Unfortunately, this would not be officially tolerated. Prior to 1591, the Portuguese allowed immigration into their colonies by anyone of the Catholic religion. However, after that date, they adopted the Spanish law which excluded all aliens.
Hence, if the USE wishes to trade openly in Belem, or indeed anywhere in Latin America, it must do so through Spanish or Portuguese intermediaries. Spanish agents are fine if you want to use them to arrange shipments of Castilla rubber. However, it is doubtful that they can help you get Para rubber from Brazil. Despite Spanish rule, it is not clear that the Belem authorities will be receptive to Spanish agents.
In 1637, a small Spanish party (two friars and six soldiers), originating in Ecuador, descended the Amazon. One friar was sent to Lisbon for questioning, the rest of the party was detained, and later that year Pedro de Teixeira took a force of over 1,000 men upriver, reaching Quito almost a year later. The obvious purpose of this expedition was to strengthen the Portuguese claim to the Amazon Basin. (Smith, 143-8)
Consequently, to set up a quasi-legitimate rubber collecting operation based in Belem, the USE may need to identify the Portuguese equivalent of the Spanish testaferros. There are conversos (Jews who converted, at least publicly, to Christianity) in Brazil, and the Nasi family may be able to identify possible recruits from this community.
You can avoid this rigmarole if the inhabitants of Belem are willing and able, despite the law, to trade with foreigners. Such illicit trade was common in the Caribbean. The visitors might land a party in a secluded cove, and it would then make surreptitious contact with the locals. They could approach the harbor, and plead that they had been driven off course by a storm. They could "win their market at sword's point"; make a show of force and then, perhaps after real or pretended resistance by the local garrison, receive the governor's license to trade. (The foreigners might even pay duties or license fees.) Or a neglected settlement might welcome them openly, without coercion, as seems to have occurred on Trinidad in the early 1600s. (Naipaul, 60-70; Burns, 142-6)
Even if the local Portuguese are uncooperative, you may be able to infiltrate the Amazon region. Belem itself is at the mouth of the Para, which lies to the south of the Amazon and is not directly connected to it. Hence, in ord
er to discourage further foreign activities on the Amazon, Portuguese also built a new fort at Gurupa (Furneaux, 50), which overlooks the more southerly of the two main entry channels. Nonetheless, it may be possible to sneak into the Amazon by way of the northerly channel, the Canal do Norte.
The odds are improved if we are forearmed with detailed knowledge of its navigational peculiarities. Grantville's maps of the region are probably not particularly detailed, but Dutch sailors did serve from time to time on Portuguese ships, and may have some knowledge of these waters. Or there may be Portuguese mariners who are sufficiently estranged from their native land (perhaps because it is under Spanish rule) to be willing to guide us through.
Unfortunately, the Para rubber trees do not lend themselves to snatch-and-run operations. While they are prolific latex producers, their wound-healing mechanisms assure that only a small amount of latex is extracted on a given day. Nor has it been found to be productive to fell the trees in order to get a "one time" bonanza. So that means lingering in the Amazon, for weeks or months, until one has collected an adequate cargo of rubber. Which, in turn, increases the risk that native allies of the Portuguese will report your presence, guaranteeing that you have to fight your way back to the ocean.
It is safe to say that it is impossible to establish a USE trading post in the lower Amazon, and supply it on a continuing basis by ships traversing the entrance channels, without either obtaining the permission of the king of Spain, or overwhelming the Portuguese military forces in the region.
While you cannot hope to collect a substantial amount of rubber in the lower Amazon without your presence becoming known to the authorities in Belem, a stealth run could be made for the purpose of collecting seeds. However, we then run up against the problem that Hevea seeds have a very short period of viability. Hence, for such a mission, you really want to have a ship with both sails and steam engines. It enters and leaves the river quietly, under sail, and it steams home. (Ocean steamers can navigate the Amazon as far upriver as Iquitos, 2,300 miles from the ocean.) When Wickham needed to collect Hevea seeds for Britain in 1876, he chartered the steamship Amazonia. The "seed raid" is probably impractical prior to the conclusion of the Baltic War.
Another option is to seek out a "back door" into the Amazon basin. The shortest routes are through the Guyanas, the coastal region between Venezuela and Brazil. The stretch separating the mouth of the Orinoco River (Venezuela) and the mouth of the Amazon was known in this period as the "Wild Coast," because of the paucity of European habitation. The Spanish made no effort to settle it, and minimal effort to control it (Hemming, 182-3; Burns, 173).
Of the possible routes, the most interesting one is probably the one exploited in our timeline by the Dutch. Beginning in 1617, they established settlements on the Essequibo River (in British Guyana). They ascended the Essequibo River, then its tributary, the Rupununi, portaged over to the Rio Branco (the Rupununi savannah is flooded over during the rainy season), and then sailed on to the Rio Negro, the Amazon, and the Madeira. Once in the Amazon basin, they traded in iron and slaves. In OTL, the Portuguese eventually blocked this traffic, first with a fort at Manaus (1667), and later with a mission at the mouth of the Rio Branco (1720). (Furneaux, 51; Guyana.org; Burns, 173-6, 196, 214)
The EB11 entry for "Guiana" warns, "The Essequibo can be entered only by craft drawing less than 20 ft. and is navigable for these vessels for not more than 50 m., its subsequent course upwards being frequently broken by cataracts and rapids." So, if we use this route to trade for rubber, much of the traveling would have to be done by canoes. This would result in much higher transportation costs and longer transportation times than if we could take full advantage of the Amazon River.
There are alternative routes which look shorter on paper, but are less likely to be practicable. For example, one could ascend the Maroni and Litani Rivers (the border between Suriname and French Guyana), and portage over to the Paru or the Jari tributaries of the Amazon, but that requires crossing the Tumucumaque Mountains.
These routes also allow you to play "Johnny Rubber Seed": collect Hevea seeds in the Amazon basin; plant them on your return trip, at a marked location, while they are still viable; and come back four years or so later to collect the seeds from your transplants. Eventually, you will get the seeds to the coast and onto a ship.
It is not strictly necessary to cross the Guyana Highlands into the Amazon Basin in order to find rubber trees; there are some in the Guyanas. These are not the famous Hevea brasiliensis, but another Hevea species, Hevea guianensis. Hence, USE exploration of the Guyanas could be somewhat improvisational; we try to use the river system to reach the Amazon Basin, but if we find rubber trees along the way, we exploit them.
* * *
The third possible source of natural rubber in the New World is the Ceara Rubber Tree (Manihot glaziovii). "Ceara" is the name of a province in northeast Brazil (the part that bulges toward Africa). Ceara was pretty much ignored by Europeans prior to 1649. However, USE exploration in that region could attract the attention of the Dutch and Portuguese, who are struggling for control of the sugar plantations farther south. The plant we are seeking is native to the sertao (the arid highlands), and hence may also occur in the hinterland of Rio Grande del Norte, Paraiba, Pernambuco and Bahia (the first two are confirmed by Polhamus, 51). Keep your distance from Bahia and Recife if you don't want to be drawn into the Dutch-Portuguese war.
* * *
We only have a written description of the Pernambuco Rubber Tree (Hancornia speciosa), and it occurs in the very region that the Dutch and Portuguese are fighting over. If this rubber enters commerce, it most likely will be the result of their own activity.
* * *
Finally, there is guayule (Parthenium argentatum). This occurs in the Chihuahua desert region of Mexico and Texas, and was used during World War II as an emergency source of rubber. This desert is the largest one in North America, covering over 200,000 square miles, and including parts of modern Mexico, Arizona, New Mexico and Texas. There is a map in Collier's Encyclopedia (CE) which shows where guayule is found in the wild.
The easiest route into the region is by way of the Rio Grande river. Unfortunately, there are Spanish settlements on the river, at San Juan Bautista and El Paso del Norte, as well as to the south, at Janos, Chihuahua, Parral and Monclova (Spanish Bannon, 4). Hence, the least protected route would be from the northwest, through Apache and Comanche territory. Even to reach that territory, you will have to make a long journey, most likely up the Llano River and then south.
Since you could not expect to make this journey repeatedly without interdiction by Spanish forces, you would mostly like want to do it just to gather seeds and seedlings for transport to a safer region, perhaps one of the Caribbean islands, or somewhere in Africa or in Italy.
Asia
The position of Asia in the natural rubber industry is a curious one. While there are native rubber-producing plants, OTL Asian rubber production is mostly based on the transplanted Hevea brasiliensis. The up-timers have a great advantage over their late-nineteenth-century forebears; they know where Hevea production was most successful. The World Book Encyclopedia says, "more than 80 percent of the world's natural rubber grows on plantations in the Far East, chiefly in Thailand, Indonesia and Malaysia." Natural rubber-producing regions are mapped by both WBE and CE; they are in rough yet incomplete agreement.
Based on those maps, OTL Thailand has rubber plantations in the valley of the Chao Phraya. The early seventeenth-century Siamese capital was on that river, at Ayudhya (Ayutthaya). Thailand was then a powerful and cosmopolitan kingdom, which traded vigorously, mostly with Portugal, Spain, the Philippines, China and Japan, but also with England, the Netherlands, Denmark, and the Muslim states of the Indian Ocean region. There are no European forts in the Siamese kingdom; Europeans are most likely to be found in Ayudhya or in Pattani, as traders or in the royal service. (Van der Kraan; Polenghi; Thai MFA). While the Europeans may offer us competiti
on, they don't dominate the polities of the Thai state, and hence cannot exclude the USE. As of RoF, Thailand is ruled by an usurper, King Prasat-Thong (1629-1656). Despite the usurpation, Thailand offers sufficient political and economic stability to make it reasonable to establish Hevea rubber plantations there, knowing that the trees will not be tappable for five to seven years. The one problem with Thailand is that it was not densely populated in the 1630s.
The Grantville encyclopedias also reveal that OTL rubber plantations of Malaysia and Indonesia are in the Malay peninsula (southern half), Sumatra, Java, and along the coast of Borneo (principally on the north and west coasts, but there are smaller clusters near Saraminda and Bandjarmasin). Of these regions, the only one which is densely populated is Java. European activity is much greater in this region than in Thailand, as the area receives trade from the Spice Islands (the Moluccas). In 1632, the principal European forts were those of the Portuguese at Malacca (Malaya), the Dutch in Batavia (Java), and the Spanish in Tidore and Ternate( Moluccas). You can expect to run into both Dutch and Portuguese traders pretty much anywhere in Malaysia and Indonesia.