The University of Vienna's Botanical Garden encompasses numerous special collections that play an important role in species protection and research. Here is a selection of these collections: 


Aroids – Araceae (119 genera, 6450 species worldwide)
The aroid (or arum) family is highly diverse. The Botanical Garden cultivates over 1200 accessions. This collection holds about 500 taxa (species, subspecies, …) belonging to nearly 70 genera. The focus of the collection is on tuber-forming aroids. The plants serve as research objects in taxonomic and flower morphology studies.
Aroids – Araceae

The pineapple family – Bromeliaceae (59 genera, 2975 species worldwide)
Our collection of the pineapple family comprises over 3000 plants encompassing ca. 1000 taxa from about 50 genera. The focus is on bromeliads from the subfamily Tillandsioideae. The plants are used for a wide range of taxonomic, systematic and phylogenetic studies.
The bromeliad collection

Fescue – Festuca (430 species worldwide, sweet grasses – Poaceae)
The Garden cultivates somewhere around 170 fescue plants comprising 39 species and 7 varieties. Most represent Central European species that were collected in their natural habitats. The plants are study objects in flower biology, morphology, cytology and systematic/taxonomic investigations.

Gesneriads – Gesneriaceae (151 genera, 3525 species worldwide)
About 90 accessions comprising over 60 taxa from about 30 genera are being cultivated. The focus: Old World species; morphological, cytological and systematic studies; investigations on the ecology of endangered species.
The genera of Gesneriaceae
The Gesneriad Reference Web

Orchids – Orchidaceae (ca. 26,000 species worldwide)
The focus of the orchid collections is on the genera Bulbophyllum (1800 species worldwide) and Pleurothallis (550 species). We are currently cultivating over 2600 accessions encompassing 900 taxa of Bulbophyllum. In the case of Pleurothallis those numbers are ca. 150 accessions of about 100 taxa. These collections are used for genetic and morphological studies to clarify phylogenetic relationships as well as to support the work on the CITES Checklist for the genus Bulbophyllum.
Bulbophyllum project

Madder family – Rubiaceae (ca. 576 genera, ca. 12,000 species worldwide)
We are currently cultivating ca. 150 accessions of madder plants encompassing 190 species and subspecies from 70 genera. The collection serves as the basis for systematic, morphological and cytological studies and supports the revision of "critical" taxa. Our Garden is involved in an intensive collection exchange (above all for Old World species and duplicates) with the National Botanical Garden of Belgium in Meise.

Serpentine flora
A very special flora has established itself on heavy-metal-containing serpentine soils. The Garden holds ca. 40 accessions encompassing about 30 taxa, all of which were collected at various serpentine sites in Austria. A group containing some highly specialized and rare taxa from such unique sites is on display in the southern part of the Garden. The Botanical Garden is devoted to preserving the gene pool of this serpentine flora (as well as of the Pannonian group): some species are highly endangered in their natural environment. The Garden also offers an opportunity to study the population dynamics of these species.
The Serpentine Group

Pannonian flora
The Pannonian group in the Botanical Garden encompasses ca. 220 taxa (about 340 accessions) of various dryland vegetation habitats in eastern Austria (Pannonian floral province). This group is displayed in the southern part of the Garden and draws attention to the global threats facing native dryland sites. Moreover, it represents an ex-situ gene pool for a number of endangered species whose population dynamics can be studied in this display group.

The estimated numbers of species and genera in parentheses stem from Mabberley, D. J, 2017: Mabberley's Plant-Book. Cambridge University Press. 4th ed.