Cypripedium calceolus
One of his partners in botany was Joseph Whittaker of Breadsall and Morley who had practised botany in South Australia. In 1846 Harpur-Crewe and Whittaker reported on the earlier local extinction from Derbyshire of the lady's slipper orchid "Cypripedium calceolus". Whittaker's plant collecting activities began to decline around 1863 at about the time Crewe moved away to take up the position of rector in the parish of Drayton Beauchamp in Buckinghamshire. In 1864 they cooperated in the production of a manuscript list of the principal flowering plants and ferns of Derbyshire. His productive partnership with Crewe lasted for at least eighteen years.