I had no doubt that it might, indeed, be all of it. Take everything you need to get them the first time. They might not be there tomorrow. It looked to me like he had certainly followed his own advice. Now, his collection covers all of the region that was the tropics before some rather major land movements and global climate changes.
Swamps are interesting places, and apparently have been for several hundred million years.
The ones where plants sank and gradually got compressed and transformed to coal, are now called coal swamps. If you have a big saw, you can make sections of them, dissolve the matrix around the plants, and painstakingly examine the macroscopic remains. Practically, it forms the basis for understanding what coal really is. Intellectually, it has allowed Phillips and his students to document the vegetation of the Pennsylvanian age, and examine its ecology along horizontal transects through a swamp and up onto dry land. . Vertical transects built a different picture, the evolutionary and successional changes that occurred over 12 million years.