This page lists terms used throughout the catalog. As many of these terms are highly technical we feel compelled to include a summary of definitions below.

CULTIVAR NAME - The designation “cultivar” stands for cultivated variety. A plant becomes a registered cultivar when it is named either by the breeder or the person registering this variety with the International Cultivar Registration Authority (ICRA). The international data base for cultivar names is maintained by the International Society for Horticultural Science (ISHS) and their designated ICRA for the genus Paeonia(Peony) is the American Peony Society (APS). All official and recognized peony names are registered with the APS. Duly registered cultivars are put into single quotation marks after successful registration. At that time the field name or trade name becomes a cultivar name. Trade names do not have single quotation marks and are often made-up marketing names used by importers and distributers. Made up catalog names and trade names have no standing other than being deceptive as they are frequently used to rename established and duly registered old cultivars. You may check the validity of a cultivar online by accessing the American Peony Society data base for registered peony names.

ORIGINATOR - Surname and year of name publication, in printed publications enclosed by parentheses, follows the peony name. When two surnames are shown, the first is normally the one who initially recognized the value of the plant, typically the breeder; the second person registered this variety and established the name.

CULTIVAR GROUPS - Hollingsworth Peonies follows the International Code of Nomenclature for Cultivated Plants (ICNCP). This convention recognizes 6 cultivar groups for peonies. For more information visit the section page Cultivar Groups.

BLOOM PERIOD - Peonies flower once a year, here in NW Missouri from late April to early June, which equates to roughly 7 weeks. For more information visit the section page Bloom Periods & Bloom Weeks.

BLOOM WEEK - It is calculated from the midpoint, week 4, which is defined by the bloom time of ‘Red Charm’. Each cultivar is assessed by how much earlier or later it blooms compare to ‘Red Charm’. For more information visit the section page Bloom Periods & Bloom Weeks.

FLOWER FORM - Flower anatomy and flower form are an inherited trait and therefore constant throughout the plants of any given cultivar. The flower form is a cultivar specific trait. For more information visit the section page Flower Form.

HEIGHT - The actual height observed at any given geographical location is subject to their prevailing climatic conditions such as precipitation, intensity of the sun, wind and temperature. At Hollingsworth Peonies, we prefer using the "relative scale", using a more general but appropriate representation of height. For more information visit the section page Height.

USDA ZONE - Herbaceous peonies grow in cold and cool temperate climates, areas with enough winter chill to induce dormancy and flower bud formation. For more information visit the section page USDA Plant Hardiness Zone Map.

ITEM NUMBER - We use the item number system to uniquely identify our peony varieties. It is assigned only once for a specific peony cultivar. We start numbering our advanced seedling in the field. As a seedling may become a commercial cultivar this seedling number becomes the item number you find in our catalog.