The Department of Plant & Molecular Biology maintains a herbarium which includes about 4000 wet and dry preserved specimens.  The herbarium collection covers most of the important tropical plant families, lichens, algae, bryophytes and ferns found in Sri Lanka.  Herbarium specimens prepared by B Sc (Special) degree students each year results in the gradual enrichment of the herbarium.

The Department of Plant & Molecular Biology maintains living specimens of fungal isolates for research and teaching purposes. Currently the fungal culture collection contains several species of fungi, many of which are unique to tropical forest ecosystems.