He was instrumental in describing the flora of the west of North America, then very poorly known to Europeans; he was particularly active in the Rocky Mountains and northern Mexico, one of his constant companions being another German-American, the botanical illustrator Paulus Roetter.

His father, Julius Bernhardt Engelmann, was a member of a family from which for several successive generations were chosen ministers for the Reformed Church at Bacharach-on-the-Rhine.

Julie Antoinette was Julius Engelmann's coadjutor in the school for young women, and its success was largely due to her management and tact.

Assisted by a scholarship (founded by the “Reformed Congregation of Frankfurt”), in 1827 he began to study sciences at the University of Heidelberg, where he met Karl Schimper and Alexander Braun.

It was devoted to morphology — mainly to the structure of monstrosities and aberrant forms of plants — and was illustrated by five plates of figures drawn and transferred to the lithographic stone by the author's own hand.

Its subject was so directly in line with that of a treatise on the metamorphosis of plants by Johann Wolfgang von Goethe that it was heartily welcomed by the poet-philosopher, whose own life was then approaching its close.

In addition to his duties assessing land investment opportunities, he also spent time on botanical travels, first visiting Thomas Nuttall in Philadelphia.

For the purpose of forming a correct judgment of the lands of the new country to which he had come, he made many long, lonesome, and often adventurous horse-back journeys in Illinois, Missouri, and Arkansas.

During the three years that had passed since he left his native land the slender means he brought with him became exhausted, and he began the practice of his profession in absolute poverty.

At that time St. Louis was little more than a frontier trading post, but Engelmann had strong faith in its future greatness, and he lived to see it become one of the chief cities of the United States.

Upon reaching New York City, Engelmann for the first time met Asa Gray, already the most noted of American botanists, and the friendship between those two eminent men thus begun was broken only by death.

Then, and long afterward, a large proportion of the inhabitants of St. Louis were of French and German-speaking families, and his familiarity with those languages, as well as with the English, gave him great advantage in extending his practice.

Illustrating this fact, as well as Engelmann's energetic manner, his son relates the following incident: “It was a bitter, sleety winter night, when the ringing of the doorbell awoke me, and I heard an urgent call for father from the messenger of a patient.

So I helped him down the icy steps, through the blinding sleet, into his carriage, and off on his mission of mercy.” Engelmann devoted himself to his medical practice, but in his later years made a specialty of botany.

One of these vacations extended from 1856 to 1858, the greater part of the first summer having been spent in botanical work at the Harvard gardens and herbarium in companionship with Asa Gray.

These visits to Europe were also the occasions of frequent and familiar personal interviews with men whose names were well known to the scientific world, such as Joseph Dalton Hooker, Alexander Braun, De Bary, Virchow, and others.

[1] In the 1870s French vineyards came under attack by a small insect, Phylloxera vastatrix, an aphid-like pest which sucks sap from the roots of grape vines.

In addition, Vitis riparia, a wild vine of the Mississippi Valley, did not cross pollinate with less resistant species, the cause of previous grafting failures.

His condition changed but little during the remainder of the winter, but when in the spring C. S. Sargent came with the proposition that he should join him in a journey through the forests of the Pacific Coast region he accepted it.