His father Wulff Lazarus Wallich (1756–1843) was a Sephardic Jewish merchant originally from the Holsatian town Altona near Hamburg, who settled in Copenhagen late in the 18th century.

[citation needed] Wallich attended the Royal Academy of Surgeons[a] in Copenhagen, where his professors trained in the botanical science included Erik Viborg, Martin Vahl, Heinrich Christian Friedrich Schumacher and Jens Wilken Hornemann.

[5][2] He obtained the diploma from the Academy in 1806, and at the end of the year was appointed as surgeon in the Danish settlement at Serampore, then known as Frederiksnagore in Bengal.

When the British East India Company took over Frederiksnagore,[b] Wallich was imprisoned,[2][5] but released on parole in 1809 on the merit of his scholarship.

[4][7] From August 1814, Wallich became an assistant surgeon in the East India Company's service and resigned as superintendent of the Indian Museum in December 1814.

In 1822, at the behest of his friend Sir Stamford Raffles he travelled to Singapore to design the botanical garden, but returned to Calcutta the following year.

The specimens in the catalogue were either collected by Wallich himself or from other collectors around the same period, including Roxburgh, Gomez, Griffith and Wight.

Two years later in 1821, he was coferred the degree of honorary doctor at the University of Copenhagen and in 1826, elected member of the Royal Danish Academy of Sciences and Letters.

[14] Wallich had suffered deteriorating health for many years, at one time contracting cholera, and he was finally obliged to resign his post in 1846 and retire to London, where he became vice-president of the Linnean Society, of which he had been a fellow since 1818.

Another part of the collection is the Central National Herbarium of the Botanical Survey of India in Calcutta, making in all about 20,500 specimens.