Alexander von Humboldt, the extraordinary plant collector

From 1799 until 1804, Alexander von Humboldt and his traveling companion Aime Bonpland journeyed through today's Venezuela, Cuba, Colombia, Ecuador, Peru, Mexico and the United States. During this time they collected thousands of plant specimens, then dried and prepared them to be sent back to Europe for further study, like this Dasyphyllum argenteum, which is found only in Ecuador.

Besides plants, the pair also gathered seeds and fruits (nuts). Yet Humboldt was more interested in the totality of nature, so much of the actual plant collecting was done by Bonpland, who was a trained botanist. Still, both made copious notes along the way. Humboldt had an eye for detail and was interested in palms and orchids — like this Catasetum maculatum, which he drew himself.

In a bid to make sure his plants made it back to Europe, Humboldt divided the collection and sent it in separate shipments. Once the specimens were safe in Europe, he also sent them to friends and collaborators. So there was never one complete set and no one can say how many plants were collected and survived the Atlantic crossing. Here a Werneria pumila, a flowering plant found only in Ecuador.

After returning to Europe in 1804, Humboldt traveled to Germany and Italy before settling in Paris for two decades to work on his Latin American research. Soon afterward, he was ready to publish his first book on the journey. "Essai sur la géographie des plantes" brought together all he knew from years of botanical observations. It is a cornerstone of plant geography. Here a Adiantum varium fern.

Paying all the bills himself, Humboldt in the end took over 30 years to complete 32 volumes on his American journey, and even then much original source material went unused. Many of the books are large folios in French with prints showing scenes, maps and animals. But it was the botanical books that set the world on fire with hand-colored images like the one of this Corallophyllum caeruleum.

Perhaps surprisingly, most of the research and writing for the botanical books was done by others — first Bonpland, who lost interest and went back to South America, then Karl Sigismund Kunth. In all they produced 15 volumes dedicated to the plants of Spanish America. The first sheets were printed in 1805, the last pages in 1834. Here a Culcitium reflexum, notice the little stars in the flower.

It wasn't just that Humboldt collected so many plants or published so many books; it was the quality of those books. They were the first to closely document the location and altitude where specimens were found. Many of the prints are based on drawings by Pierre Jean Francois Turpin, one of the greatest botanical artists to ever pick up a pen. Here a detail from an Attalia amygdalina palm tree.

But the hard work started in the field. Humboldt and Bonpland filled six notebooks with 4,528 plants (with a few gaps). They numbered them and gave preliminary determinations, descriptions and location information in French, Latin or Spanish. In some cases, they even made ink impressions of plants on paper. Here a Masdevallia uniflora; it may look like a tulip, but is actually an orchid from Peru.

The question always comes up about how many plant specimens Humboldt actually collected. The answer varies so greatly that even Humboldt quoted contradictory numbers — anywhere from 4,500 to 60,000. What really matters, though, is the speed with which he published the findings and the sumptuousness of the books. He was even able to make Mariscus pycnostachyus, a marshy grass, look great.

The adventures did not limit themselves to land either. They took plants from the Andes and the bottom of the ocean. Not all the plants brought back or later published were new though. Still the scientists could not resist naming some after themselves. Here a detail of a Zonaria kunthii, an algae today known as Dictyota kunthii and named in honor of Humboldt collaborator Karl Sigismund Kunth.

Dried, pressed plant collections, otherwise known as a herbarium, are valuable resources. An historical one like Humboldt's that is over 200 years old and spread between Paris' Natural History Museum and Berlin's Botanical Garden is important since it is a time capsule. These shelves in a vault of the Botanical Museum in Berlin hold part of their unique collection of 3,000 Humboldt plant specimens

Sadly, the Berlin collection suffered in World War II. When bombs fell on the Botanical Museum only part of the irreplaceable herbarium had been put into a bank vault for safety. The rest was a near-complete loss. Much of what scientists worked so hard to collect was gone in an instant. Here one of the survivors, a leaf from a Bertholletia excelsa, the Brazil nut tree. Now it's under lock and key.

Since the war Berlin's Botanical Garden and Museum has replaced or built up their collection of Humboldt's botanical books. Besides putting on small exhibitions, they have also digitized his herbarium and made it available online. His labors in the Spanish American colonies and afterwards in Paris were so pioneering that scholars still scour his notes to learn about his scientific fieldwork.

No matter how important Humboldt's work is to researchers, he left behind many of the most stunning botanical prints ever created. Anyone can enjoy them without knowing their history or how heavy the books are. Though the artists sometimes used improbable colors, the images are nonetheless beautiful like this Oncidium pictum orchid. (Source for historical images: Botanical Museum Library, Berlin)