Plant Systematics Section

Zdjęcie działu pierwszegoPlant Systematics Section is distinguished for its particular structure of rise beds. Its aim is to show the rules of scientific classification of plant species, that are grouped by their phylogenetic relationships. On individual, neighbouring with one another beds specimens of genera belonging to the same family can be found, whereas the latter is placed in a higher taxonomic rank that is scientifically called an order. Regularly arranged floral beds help to present and trace those relationships. Until recently the collection of plants in the section was organised according to the classification system proposed at the turn of the 19th and 20th centuries by a German botanist Adolf Engler (1844–1930), who was born in nowadays Żagań (Lubuskie region). Although the system has not been used by botanists for many years, it was maintained for historical reasons. However, in the last decades mostly because of the development of phylogenetic methods and the use of molecular data a totally new system has been created – APG (Angiosperm Phylogeny Group), which can measure evolutionary relationships among species in a very precise way. Some of the findings were a surprise even for the scientists, as they revealed some new aspects of plants’ evolution. It seems that APG, unlike former systems of classification, reflects the true evolution of plant species, which resulted in modernisation of the section and change of the historical arrangement of plants. Therefore, many plants in the section are now having their places changed and the process will take a few years. The section is di­vided into three separate parts that inclu­de plants grown according to the increasing level of complexity of their structure. In the first part (Systematics I) the simplest vascular plants can be found. They are represen­ted here by ferns. As beautiful examples of them serve here Royal Fern (Osmunda regalis) and Ostrich Fern (Matteucia struthiopteris). Used in medicine, gymnosperm Ephedra (Ephedra sinica) functions as a curiosity in the section. The simplest angiosperms are represented in the section by the family of Schisandraceae, Star Magnolia (Magnolia stellata), the Magnolia family (Magnoliaceae) and the Laurel family (Lauraceae) – White Sassafras (Sassafras albidum) and Bay Laurel (Laurus nobilis), that is taken out from a greenhouse in summer. Due to the recent changes specimens of monocotyledons have been located here. The group is represented here by the Arum families (Araceae) – Arisaema, Sauromatum, Lilium, Amaryllidaceae and True Grasses (Poaceae). They are followed by numerous specimens of the early evolutionary lineage of the so called eudicots, that is the families of Papaveraceae, Buttercups (Ranunculaceae) and Buxaceae. Collections of other families, such as: Knotweeds (Polygonaceae), Carnations (Caryophyllaceae), Amaranths (Amaranthaceae) or even Cacti (Cactaceae) and meridian Stone Plants (Aizoaceae) can also be found in the section. Reaching an impressive size Japanese Knotweed (Reynoutria japonica) together with American Pokeweed (Phytolacca americana) function in the section as curiosities. Other specimens of plant families followed in succession can be found in the section Systematics III. Systematics II includes plants that are classified as the so called Rosids, a large clade of families related to the Rose family (Rosaceae). More primitive families of Peonies (Paeoniaceae) and Saxifragaceae open the section. They are followed by, for example the Spurge family (Euphorbiaceae), Legume family (Fabaceae), Rose family (Rosaceae), Nettle family (Urticaceae), Beech family (Fagaceae) and Gourd family (Cucurbitaceae). The section also includes the families of Geranium (Geraniaceae) and Willowherb (Onagraceae). Systematics III includes plants belonging to a big group of the so called Asterids (relatives of the Asteraceae family). A flower bed of the Dogwood family (Cornaceae) and Hydrangeaceae family opens the section. Other representatives of the section have flowers of joined petals that form trumpets or tube-like flowers. As good example serves here Periwinkle (Vinca), Comfrey (Symphytum), Morning Glory (Ipomoea) and Angel’s Trumpets (Datura). The section includes also many specimens of the Lamiaceae family, for example English Lavender (Lavandula angustifolia) and Sage (Salvia officinalis) as well as the Asteraceae family. In the future Parsley (Apiaceae) and Aralia (Araliaceae) families will be set here with Spikenard (Aralia) and Ivy (Hedera) as their representatives.