Land F/X Plant Database Nomenclature Protocol
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Land F/X Plant Database Nomenclature Protocol

Did you know you can add your own plants to our wiki-based plant database? This article lays out how new entries to the Land F/X plant database should be formatted, and why. This information is based on International Code of Nomenclature for Algae, Fungi, and Plants by the International Association for Plant Taxonomy (IAPT) and International Code of Nomenclature for Cultivated Plants by the International Society for Horticultural Science (ISHS), combined with the historic entry format of the Land F/X plant database.

Notes on Plant Name Accuracy & Consistency

Our team takes nomenclatural accuracy seriously, while also understanding that our users did not create the errors or nuance in naming that exist in the horticulture industry. Here, we lay out the rules based on the various nomenclature codes, but the database reflects the reality that these rules are often broken by the horticulture industry itself. Regardless, we enter names as correctly as possible so users communicate effectively with their clients while retaining professional accuracy.


Our database manager vets every plant name entered into the database using the rules spelled out below. We spend a great deal of time on each entry to ensure the name is correct, looking at multiple nursery websites, botanical garden websites, International Cultivar Registration Authorities (ICRA), and even plant patent information. We are currently in the process of cleaning up entries in the database to maintain consistency and accuracy. If you find a mistake or want to know why a plant name is displayed in a certain way, send us a technical support ticket describing the issue for our staff horticulturalist, who will then address the discrepancy.




The Importance of Consistent Naming Rules

Consistency in the use of names for horticultural plants is essential because it facilitates effective communication between the creators and users of plant material. From the plant breeder to the grower, landscape architect, and landscape contractor, accurate name use ensures that everyone is discussing the same piece of plant material. Because of the existence of specific names, bodies of information about each named plant can be built and shared far beyond what would otherwise be possible. To keep that information accessible, however, the name must be communicated successfully between users. When you don't know the correct name of a plant, you have no way to access the wealth of information that likely exists about that plant in print or Internet resources.


The genus is entered within the Genus field in our plant entry dialog box.


The first letter of the genus is always Capitalized, and genera (plural of genus) are italicized.


  • Acer rubrum 'PNI 0268' // October Glory® Red Maple
  • Agapanthus africanus 'Queen Anne' // Queen Anne African Lily

We're currently working on engineering a way for these names to italicize automatically.

Entering a plant genus




When Land F/X users enter new plant names, our database manager will check the validity of the entered names. New genera are checked for taxonomic accuracy using multiple taxonomic resources, including Global Biodiversity Information Facility (GBIF), The Plant List, and Integrated Taxonomic Information System (ITIS).


Hybrid genera are specified by an x before the name used to classify them. (Typically, this name is determined by the horticulture industry or plant taxonomists). To be truly correct, the multiplication sign × (rather than a lowercase x) should be used to denote hybrids. For ease of entry, Land F/X uses a lowercase x. See IAPT botanical nomenclature code Article H.3.1.


Entering a species name

The species name, botanically known as the specific epithet, is entered into the Species field.


Specific epithets are not capitalized but are are always italicized. (60F.1, IAPT).



  • Acer rubrum 'PNI 0268' // October Glory® Red Maple
  • Agapanthus africanus 'Queen Anne' // Queen Anne African Lily

As with plant genera, we're currently working on engineering a way for these names to italicize automatically.




If you need to enter any plant of hybrid origin, you can file it under Genus x. However, if you are aware of more specific parentage, you can use this information instead – ideally with the female parent listed first (IAPT Code Article H.2). x hybridus will be used under specific instances of a taxonomically recognized hybrid (that is, a hybrid named by a taxonomist) unless the name is used widely in horticulture as a catch-all for hybrid cultivars.


Any hybrid with more than two species in its parentage will be listed under the species x or x hybridus.(Depending on the species, the latter is sometimes used). Hybrids of just two species will be listed as species 1 x species 2 or just under the Genus x _______. Plants may occasionally be listed in both ways at one time.


New plant names entered by users will always be vetted by our database manager for taxonomic validity. If a name is still widely in use in the horticulture industry, it will likely be added even if not taxonomically correct.

We hope to engineer a system that will notify users of name changes and redirect from older names to the most up-to-date taxonomy. The reason for redirecting rather than removing out-of-date names is that users might still occasionally use older names if the nursery supplying plants for a project is still using those names. Plus, designers who simply use a name they know would be notified of the new name, which would eliminate the frustration of finding out that the old name has disappeared from the database.


Varieties are entered in the Variety field.


The variety includes any part of a scientific name that goes beyond the level of specific epithet (species) – so, any third word in a botanical name that is italicized, be it a variety (var.), subspecies (subsp.) or form (f.).


To maintain consistency with our existing plant database style, varieties are entered without anything indicating whether they are a variety or a subspecies. At some point, we may update this convention to reflect correct naming rules, which would include qualifiers for items such as variety (var.), subspecies (subsp.), and form (f.).

Entering a variety


Adding a cultivar

Cultivars are also entered into the Variety field.


 Cultivars are always in 'Single quotes' (Article 14.1, Scripta Horticulturae). The first letter of each word is always capitalized, and italics are not used.



  • Acer rubrum 'PNI 0268' // October Glory® Red Maple
  • Agapanthus africanus 'Queen Anne' // Queen Anne African Lily

Notes on Cultivar:

Hyphens: If a cultivar includes one or more hyphens, the word after the hyphen is not capitalized unless it is a proper noun (Article 8.A.1, Article 21, Scripta Horticulturae). The code now considers it incorrect to denote cultivars using "cv." – plus this style is not consistent with the general format of the Land F/X plant database, so we do use this format.


Latinization: Cultivar names should not be latinized unless they are from before January 1, 1959. Examples of latinized cultivars include 'Atropurpurea', 'Alba', 'Aurea', and 'Glauca.' Despite the existence of this rule, it is often not followed. As a result, our database commonly includes cultivars that are formatted incorrectly. One considerable caveat to this rule: If a plant variety is no longer taxonomically recognized, it can be formatted as a cultivar instead. This allowance leads to a plethora of latinized cultivar names.


Trademark phrases are entered into the Common field.


According to ISHS, trademark phrases "must never be given nomenclatural status" (Division IV) and should therefore not be displayed in such a way that they may be confused with names or epithets. This includes displaying trademark phrases within 'single quotes' as if they were cultivars (Article 17.1, Scripta Horticulturae).


Example: Acer rubrum 'PNI 0268' // October Glory® Red Maple

Adding trademark phrases

Why trademark names shouldn't be entered as cultivar names:

Because of the ISHS reasoning mentioned above, trademark names are generally not entered into the Land F/X database as cultivar names unless it is not possible to find the actual cultivar name. Entering trademark names as if they were cultivars may make it easier to communicate the desired plant material and may look cleaner, but this practice is incorrect from a nomenclature standpoint.


Avoiding using trademark names as cultivar names is especially important for species such as roses, where one cultivar can have many different trademarks, or many different cultivars can be sold using the same trademark. Unlike cultivar names or plant patents, trademarks are not tied to specific plant material, and are therefore an unreliable way to attempt to cite specific plant material – even though they are easier to remember. We hope our keyword search function will help with the correct placement of trademark phrases within botanical plant names.

Common Name

Adding a plant common name

The common name is entered in the Common field. It is preferred to include the entire common name of that species, along with either a trademark phrase or the cultivar name, repeated from the variety box.


The common name never includes 'single quotes' as these denote that the cultivar name exists as part of the scientific name. Hence, when we use the cultivar name as part of the common name, it does not get single quotes.


A plant's common name includes its cultivar name (not in single quotes), along with any other trademarked term and a species common name.





  • Acer rubrum 'PNI 0268' // October Glory® Red Maple
  • Agapanthus africanus 'Queen Anne' // Queen Anne African Lily

The bolded text in the examples above represents what should be entered into the Common name field when entering a new plant name. Each word of the plant common name in the database is capitalized, which must be done manually by users entering a new plant

Parentage Unknown

If parentage is truly unknown after some searching, the hybrid category can be used (Genus x 'Cultivar'). We encourage you to avoid this practice if possible. However, we've also found it better to list plants with unknown parentage as hybrid than to list them under the wrong species.

Last modified on Thursday, 07 April 2022 12:16

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