Just a guess if maybe Arthur Joseph Constable-Maxwell-Stuart b. 31 May 1845, d. 7 November 1942 is the person honered in:
I have no idea if this guy was ever in Bolivia. Maybe the same person as mentioned as (Arthur Maxwell-Stuart, Esq.) in Gardeners' Chronicle, Horticultural Trade Journal Vol 95 p. 392? Here
Arrived at Scarthingwell Park, the members were met by the Hon. H. C. Maxwell-Stuart, J.P., and two of his sons, who spared nothing that lay in their power to promote the enjoyment of the members. Some of the party elected to take an extended route northwards, under charge of Major Thompson, and left the Park for Saxton Carr and the woods about Towton Spring. Most of the work done on this route was botanical. From Towton Spring the route lay through the wood known as Renshaw, and up the valley of the River Cock, which is here a clear and winding and very swift stream. On Towton Battle-field the remainder of the party were met; they had spent a most profitable hour in examining the superb collections of foreign lepidoptera and birdskins, as well as of minerals, agates, &c., which had been collected and brought home by the Hons. Herbert and Arthur Maxwell-Stuart. After this they had investigated the lake by means of boats, and thence — under the able guidance of Mr. B. Saynor — proceeded to the battlefield f Towton, to rejoin Major Thompson's contingent, afterwards making their way to Sherburn village.
This could fit as the father the Hon. Henry Constable-Maxwell-Stuart of Traquair was mentioned in the same article. Herbert Joseph Constable-Maxwell-Stuart may his brother.