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45-465: Drimia is a genus of African, south European and south Asian flowering plants . In the APG IV classification system , it is placed in the family Asparagaceae , subfamily Scilloideae (formerly the family Hyacinthaceae). When broadly circumscribed , the genus includes a number of other genera previously treated separately, including Litanthus , Rhodocodon , Schizobasis and Urginea . One of

90-557: A species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in the nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

135-399: A description of a particular plant practically loses its value. Use of these terms is not restricted to leaves, but may be applied to morphology of other parts of plants, e.g. bracts , bracteoles , stipules , sepals , petals , carpels or scales . Some of these terms are also used for similar-looking anatomical features on animals. Leaves of most plants include a flat structure called

180-643: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

225-399: A leaf. may be coarsely dentate , having large teeth or glandular dentate , having teeth which bear glands Leaves may also be folded, sculpted or rolled in various ways. If the leaves are initially folded in the bud, but later unrolls it is called vernation , ptyxis is the folding of an individual leaf in a bud. The Latin word for 'leaf', folium , is neuter. In descriptions of

270-621: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

315-468: A position supported later by some molecular phylogenetic studies. This broad circumscription of Drimia is accepted by the World Checklist of Selected Plant Families . Other sources prefer to maintain a larger number of segregated genera. Regardless of whether a broad or strict view is taken of Drimia , it is placed in the tribe Urgineeae of the subfamily Scilloideae (or the subfamily Urgineoideae of

360-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

405-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

450-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

495-419: Is commonly used for plant identification. Similar terms are used for other plant parts, such as petals , tepals , and bracts . Leaf margins (edges) are frequently used in visual plant identification because they are usually consistent within a species or group of species, and are an easy characteristic to observe. Edge and margin are interchangeable in the sense that they both refer to the outside perimeter of

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540-596: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

585-516: Is not always clear whether because of ignorance, or personal preference, or because usages change with time or context, or because of variation between specimens, even specimens from the same plant. For example, whether to call leaves on the same tree "acuminate", "lanceolate", or "linear" could depend on individual judgement, or which part of the tree one collected them from. The same cautions might apply to "caudate", "cuspidate", and "mucronate", or to "crenate", "dentate", and "serrate". Another problem

630-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

675-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

720-535: Is to establish definitions that meet all cases or satisfy all authorities and readers. For example, it seems altogether reasonable to define a mucro as "a small sharp point as a continuation of the midrib", but it may not be clear how small is small enough, how sharp is sharp enough, how hard the point must be, and what to call the point when one cannot tell whether the leaf has a midrib at all. Various authors or field workers might come to incompatible conclusions, or might try to compromise by qualifying terms so vaguely that

765-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

810-799: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

855-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

900-469: The French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or the scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of

945-565: The Mediterranean area and Asia. About half of all the species occur in southern Africa, where species diversity is greatest in semi-arid regions with winter rainfall. Drimia generally is found in regions with seasonal dryness. Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including

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990-619: The World Checklist of Selected Plant Families accepted 100 species: In addition, 10 species described in 2015, and placed by the authors in Rhodocodon , are, as of August 2017, treated as "unplaced" in the World Checklist of Selected Plant Families, which does not recognize the genus; none have names in Drimia : The broadly defined genus has about 100 species found in Africa, including Madagascar,

1035-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

1080-429: The base for more than half their length. The genus Rhodocodon was included in Drimia by Goldblatt and Manning in 2000. The species of Rhodocodon , or the Rhodocodon group within Drimia , including D. cryptopoda , form a well supported clade endemic to Madagascar. They appear to be the product of a single invasion of Madagascar by an African species. A total of 13 species are recognized by those who separate

1125-416: The best-known species is the sea squill, Drimia maritima (formerly Urginea maritima ). Drimia intricata (formerly Schizobasis intricata ) is sometimes cultivated as a bulbous or succulent plant. Drimia species are usually deciduous , more rarely evergreen, growing from bulbs . The bulbs may be underground or occur on or near the surface. Each bulb has one to several leaves that are often dry by

1170-429: The blade or lamina, but not all leaves are flat, some are cylindrical. Leaves may be simple, with a single leaf blade, or compound, with several leaflets . In flowering plants , as well as the blade of the leaf, there may be a petiole and stipules ; compound leaves may have a rachis supporting the leaflets. Leaf structure is described by several terms that include: Being one of the more visible features, leaf shape

1215-451: The family Hyacinthaceae if this family is separated from Asparagaceae). The genus Litanthus was for a long time monotypic, with the sole species L. pusillus , before in 2000 Goldblatt and Manning included it in Drimia . A further species, Drimia stenocarpa , was added to the group in 2014. The Litanthus group is characterized by one- or occasionally two-flowered inflorescences with drooping tubular flowers whose tepals are united at

1260-593: The feminine form of the adjective δριμύς drimys meaning "bitter" or "acrid", referring to the root. The boundaries between genera within the Scilloideae are not completely settled. The situation has been described as being in a "state of flux". As early as 1977, it was suggested that Urginea be merged into Drimia , although other small genera continued to be kept separate. In 2000, Peter Goldblatt and John Charles Manning proposed including other related genera, including Litanthus , Rhadamanthus and Schizobasis ,

1305-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

1350-463: The fourth edition of Species Plantarum , published in 1799, authored by Carl Ludwig Willdenow . The name was attributed to Nikolaus Joseph von Jacquin . When describing Drimia elata (the type species of the genus) in a work published in 1797, Jacquin said that he was unable to assign it to one of the known genera, and so constructed a new one. The name is derived from the Greek δριμεῖα drimeia ,

1395-727: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

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1440-512: The genus from Drimia . The genus Schizobasis was included in Drimia by Goldblatt and Manning in 2000. As many as eight species have been described, but in 2014 these were reduced to two: Drimia intricata , including all the previously described species, and the new species Drimia sigmoidea . The Schizobasis group is distinguished by its well branched, thin-stemmed inflorescence and small, filiform leaves that are found only in seedlings, disappearing in mature plants. As of August 2017,

1485-432: The idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of the same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but

1530-628: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

1575-549: The leaf blade is divided into two or more leaflets ). The edge of the leaf may be regular or irregular, and may be smooth or have hair, bristles, or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article. The terms listed here all are supported by technical and professional usage, but they cannot be represented as mandatory or undebatable; readers must use their judgement. Authors often use terms arbitrarily, or coin them to taste, possibly in ignorance of established terms, and it

1620-418: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Glossary of leaf morphology#filiform The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is,

1665-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

1710-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

1755-526: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

1800-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

1845-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

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1890-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

1935-580: The time the flowers open. The inflorescence is in the form of a raceme , with one to many flowers. At least the lower inflorescence bracts have spurs (a characteristic of the tribe Urgineeae). The individual flowers generally last for only one to two days and have white to yellowish green or brown tepals that are either free or joined into a basal tube. The tepals often have a darker central keel. After fertilization, an ovoid capsule forms with several seeds in each locule . The seeds are black and winged. A formal description of genus Drimia first appeared in

1980-566: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

2025-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

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