[3] At this time Lindley became acquainted with the botanist William Jackson Hooker who allowed him to use his botanical library and who introduced him to Sir Joseph Banks who offered him employment as an assistant in his herbarium.

He concentrated on the genera Rosa and Digitalis and published the monograph "A Botanical History of Roses" which distinguished seventy-six species, describes thirteen new ones and was illustrated by nineteen coloured plates painted by himself.

One of Banks' friends, a wealthy merchant called William Cattley, paid Lindley to draw and describe new plants in his garden at Barnet.

[7] Lindley was appointed assistant secretary to the Royal Horticultural Society and its new garden at Chiswick in 1822, where he supervised the collection of plants.

Assistant secretary to the Horticultural Society since 1822, in 1829 Lindley was appointed to the chair of botany at University College, London, which he retained until 1860.

[5] He also lectured on botany from 1831 at the Royal Institution, including delivering the 1833 Royal Institution Christmas Lecture, and from 1836 at the Chelsea Physic Garden, starting the society's flower show in the late 1830s.Lindley described the plants collected on Thomas Livingstone Mitchell's expeditions of 1838 and wrote an Appendix to Edwards's Botanical Register of 1839, describing plants collected by James Drummond and Georgiana Molloy of the Swan River Colony in Western Australia.

[9] The Sketch, which was published during November 1839 and January 1840 in Edwards' Botanical Register and separately on its completion, was illustrated by nine hand-coloured lithographs and four wood-cuts.

During his professorship, he wrote many scientific and popular works as well as making significant contributions to the Botanical Register, of which he was the editor for many years, and to The Gardeners' Chronicle, which he co-founded with Joseph Paxton, William Bradbury and Wentworth Dilke, and where he was in charge of the horticultural department from 1841.

[5] In 1828 Lindley was elected a fellow of the Royal Society of London and in 1833 was awarded the honorary degree of Doctor of Philosophy from the University of Munich.

[14] In 1829 Lindley sought to augment his income and became professor of botany at the newly established London University while still continuing his post at the Royal Horticultural Society.

The Government commissioned a report on their future to be prepared by Lindley, Joseph Paxton and John Wilson, head gardener to the Earl of Surrey.

[8] The report recommended that the Gardens be retained but the Government did not accept their findings and proposed to abolish it, distribute the plants and pull down the glasshouses.

Although the commission was powerless to solve the problem, their report brought about the repeal of the 1815 Corn Laws which had forbidden the import of cheap wheat from America.

[18] Lindley was very industrious and published a number of works including The Genera and Species of Orchidaceous Plants, the writing of which occupied him for ten years.

[19] He was held in high regard by other botanists and was honoured by naming more than 200 species with the epithets "lindleyi", "lindleyana", "lindleyanum", "lindleyanus", "lindleya" and "lindleyoides".