Unfortunately I have been unable to find the Scientific American article to which Mees refers. Scanning through the bound volumes for 1915 and 1916 in the British Library did not reveal them. However I did find a few relevant items there and on the web.
They wrote an article on Flowers photographed by invisible light in the October 10th 1914 edition of Scientific American. Most of this demonstrated how many white flowers came out 'black' when photographed under ultraviolet light, or showed some patterning that was not apparent in ordinary light. They did comment on how flowers looked in infrared but as they usually showed up as 'white' they didn't find this as interesting.
I have photographed flowers, even dark ones, in infrared. This is an example. It is actually a dark red rose, illuminated by a flash gun.
An unusual reference to their work appears online in a 1918 edition of a magazine called Rays from the True Cross (see page 209) in an article called Insects that see 'Invisible' Light, which tells us that in an edition of Scientific American dated Jan 15 they were again investigating the appearance of flowers, which
led us recently to photograph, in ultra-violet and infra-red lights, a number of butterfliesThis article was not in any Scientific American in 1915 but the date may well refer to January 15th, possibly in 1918 ... but I have not had a chance to track that down as yet.
A further piece of research was published in Archives des sciences, March 1915 into absorption of UV and IR by arable soil and included both kinds of photographs.
It is remarkable that only a few years after Wood demonstrated that the world could look different in infrared (and UV) that these two researchers used photography to investigate aspects of this in detail. I would like to find out more about these two. Anyone know anything more?
[FYI: A useful resource of Scientific American for this period can be found at www.scientificamericanpast.com.]