Pelargonium

''Pelargonium'' () is a genus of flowering plants that includes about 280 species of perennials, succulents, and shrubs, commonly called geraniums, pelargoniums, or storksbills. ''Geranium'' is also the botanical name and common name of a separate genus of related plants, also known as cranesbills. Both genera belong to the family Geraniaceae. Carl Linnaeus originally included all the species in one genus, ''Geranium'', and they were later separated into two genera by Charles Louis L'Héritier de Brutelle in 1789.

While ''Geranium'' species are mostly temperate herbaceous plants, dying down in winter, ''Pelargonium'' species are evergreen perennials indigenous to warm temperate and tropical regions of the world, with many species in southern Africa. They are drought and heat tolerant, but can tolerate only minor frosts. Some species are extremely popular garden plants, grown as houseplants and bedding plants in temperate regions. They have a long flowering period, with flowers mostly in red, orange, or white; but intensive breeding has produced a huge array of cultivars with great variety in size, flower colour, leaf form and aromatic foliage.

Etymology

The name ''Pelargonium'' is derived from the Greek πελαργός, ''pelargós'' (stork), because the seed head looks like a stork's beak. Dillenius originally suggested the name 'stork', because ''Geranium'' was named after a crane — "''a'' πελαργός, ''ciconia, sicuti vocamus Gerania'', γερανός, ''grus''" (from ''pelargos'', stork, as we call the ''Gerania'', ''geranos'', crane).

Description

''Pelargonium'' occurs in a large number of growth forms, including herbaceous annuals, shrubs, subshrubs, stem succulents and geophytes. The erect stems bear five-petaled flowers in umbel-like clusters, which are occasionally branched. Because not all flowers appear simultaneously, but open from the centre outwards, this is a form of inflorescence is referred to as pseudoumbels.

The flower has a single symmetry plane ( zygomorphic), which distinguishes it from the ''Geranium'' flower, which has radial symmetry ( actinomorphic). Thus the lower three (anterior) petals are differentiated from the upper two (posterior) petals. The posterior sepal is fused with the pedicel to form a hypanthium (nectary tube). The nectary tube varies from only a few millimeters, up to several centimeters, and is an important floral characteristic in morphological classification. Stamens vary from 2 to 7, and their number, position relative to staminodes, and curvature are used to identify individual species. There are five stigmata in the style. For the considerable diversity in flower morphology, see figure 1 of Röschenbleck ''et al.'' (2014)

Leaves are usually alternate, and palmately lobed or pinnate, often on long stalks, and sometimes with light or dark patterns. The leaves of ''Pelargonium peltatum'' (Ivy-leaved Geranium), have a thick cuticle better adapting them for drought tolerance.

Propagation

Pelargonium are easy to propagate, just need to cut a part of the plant and put it in water to grow new roots and can be planted again. It can also be propagated by seeds, but the best option is cuttings.

Taxonomy

''Pelargonium'' is the second largest genus (after ''Geranium'') within the family Geraniaceae, within which it is sister to the remaining genera of the family in its strict sense, '' Erodium'', ''Geranium'', and '' Monsonia'' including ''Sarcocaulon''. The Geraniaceae have a number of genetic features unique amongst angiosperms, including highly rearranged plastid genomes differing in gene content, order and expansion of the inverted repeat.

Genus history

The name ''Pelargonium'' was first proposed by Dillenius in 1732,{{sfn, Dillenius, 1732, lo
De Geraniorum Differentiis p. 149
} who described and illustrated seven species of geraniums from South Africa that are now classified as ''Pelargonium''.{{cite web , last=Handlos , first=Wayne , date=2013 , url=http://www.geraniumsonline.com/18thcentury.htm , title=18th Century: Important People, Dates and Publications in the History of ''Pelargonium'' , website=Geraniums Online , publisher=Central Coast Geranium Society , access-date=3 August 2017{{sfn, Lis-Balchin, 2002, lo
Diana Miller. The taxonomy of ''Pelargonium'' species and cultivars: Classification history p. 52
} Dillenius, who referred to these seven species with apparent unique characteristics as ''Geranium Africanum'' (African Geranium){{sfn, Dillenius, 1732, lo
Geranium Africanum p. 151
} suggested "''Possent ergo ii, quibus novi generis cupido est, ea, quorum flores inaequales vel et irrregulares sunt, Pelargonia vocare''" (Those who wish a new genus can therefore call those, whose flowers are unequal or irregular, ‘Pelargonia’).{{sfn, Boddy, 2013, lo
Introduction p. 11
} The name was then formally introduced by Johannes Burman in 1738. However Carl Linnaeus who first formally described these plants in 1753 did not recognise ''Pelargonium'' and grouped together in the same genus (''Geranium'') the three similar genera ''Erodium'', ''Geranium'', and ''Pelargonium''.{{sfn, Linnaeus, 1753, lo
Geranium p. 676
} Linnaeus' reputation prevented further differentiation for forty years.{{sfn, Lis-Balchin, 2002, lo
Diana Miller. The taxonomy of ''Pelargonium'' species and cultivars: Classification history p. 52
} The eventual distinction between them was made by Charles L’Héritier based on the number of stamens or anthers, seven in the case of ''Pelargonium''. In 1774, '' P. cordatum'', '' P. crispum'', '' P. quercifolium'' and ''P. radula'' were introduced, followed by '' P. capitatum'' in 1790.{{sfn, Taylor, 2014, lo
Pelargonium
}

Circumscription

''Pelargonium'' is distinguished from the other genera in the family Geraniaceae by the presence of a hypanthium, which consists of an adnate nectar spur with one nectary, as well as a generally zygomorphic floral symmetry.{{sfn, Roschenbleck et al, 2014

Subdivision

De Candolle first proposed dividing the genus into 12 sections in 1824, based on the diversity of growth forms. Traditionally the large number of ''Pelargonium'' species have been treated as sixteen sections, based on the classification of Knuth (1912) who described 15 sections, as modified by van der Walt ''et al''. (1977-1997) who added ''Chorisma'', ''Reniformia'' and ''Subsucculentia''.

These are as follows;
* section ''Campylia'' (Lindley ex Sweet) de Candolle
* section ''Chorisma'' (Lindley ex Sweet) de Candolle
* section ''Ciconium'' (Sweet) Harvey
* section ''Cortusina'' (DC.) Harvey
* section ''Glaucophyllum'' Harvey
* section ''Hoarea'' (Sweet) de Candolle
* section ''Isopetalum'' (Sweet) de Candolle
* section ''Jenkinsonia'' (Sweet) de Candolle
* section ''Ligularia'' (Sweet) Harvey
* section ''Myrrhidium'' de Candolle
* section ''Otidia'' (Lindley ex Sweet) de Candolle
* section ''Pelargonium'' (Sweet) Harvey
* section ''Peristera'' de Candolle
* section ''Polyactium'' de Candolle
* section ''Reniformia'' (Knuth) Dreyer
* section ''Subsucculentia'' J.J.A. van der Walt

Phylogenetic analyses

All subdivision classifications had depended primarily on morphological differences till the era of phylogenetic analyses (Price and Palmer 1993).Robert A. Price and Jeffrey D. Palmer. Phylogenetic Relationships of the Geraniaceae and Geraniales from rbcL Sequence Comparisons. Annals of the Missouri Botanical Garden Vol. 80, No. 3 (1993), pp. 661-671
/ref> However phylogenetic analysis shows only three distinct clades, labelled A, B and C. In this analysis not all sections were monophyletic although some were strongly supported including ''Chorisma'', ''Myrrhidium'' and ''Jenkinsonia'', while other sections were more paraphyletic. This in turn has led to a proposal, informal at this stage of a reformulation of the infrageneric subdivision of ''Pelargonium''.

In the proposed scheme of Weng ''et al''. there would be two subgenera, based on clades A+B, and C respectively and seven sections based on subclades. Subsequent analysis with an expanded taxa set confirmed this infrageneric subdivision into two groups which also correspond to chromosome length (<1.5 μ, 1.5-3.0μ),{{sfn, Roschenbleck et al, 2014 but also two subclades within each major clade, suggesting the presence of four subgenera, these correspond to clades A, B, C1 and C2 of the earlier analysis, A being by far the largest clade with 141 taxa. As before the internal structure of the clades supported monophyly of some sections (''Myrrhidium'', ''Chorisma'', ''Reniformia'', ''Pelargonium'', ''Ligularia'' and ''Hoarea'') but paraphyly in others (''Jenkinsonia'', ''Ciconium'', ''Peristera''). A distinct clade could be identified within the paraphyletic ''Polyactium'', designated section ''Magnistipulacea''. As a result, ''Polyactium'' has been split up to provide this new section, which in itself contains two subsections, ''Magnistipulacea'' and ''Schizopetala'', following Knuth's original treatment of ''Polyactium'' as having four subsections.{{sfn, Roschenbleck et al, 2014

Thus Röschenbleck ''et al.'' (2014) provide a complete revision of the subgeneric classification of ''Pelargonium'' based on four subgenera corresponding to their major clades (A, B, C1, C2);
* subgenus ''Magnipetala'' Roeschenbl. & F. Albers Type: ''Pelargonium praemorsum'' (Andrews) F Dietrich
* subgenus ''Parvulipetala'' Roeschenbl. & F. Albers Type: ''Pelargonium hypoleucum'' Turczaninow
* subgenus ''Paucisignata'' Roeschenbl. & F. Albers Type: '' Pelargonium zonale'' (L.) L'Hér. in Aiton
* subgenus ''Pelargonium'' L'Hér. Type: '' Pelargonium cucullatum'' (L.) Aiton{{sfn, Roschenbleck et al, 2014

Sixteen sections were then assigned to the new subgenera as follows, although many species remained only assigned to subgenera at this stage

* subgenus ''Magnipetala'' 3 sections
** section ''Chorisma'' (Lindley ex Sweet) de Candolle - 4 species
** section ''Jenkinsonia'' (Sweet) de Candolle - 11 species
** section ''Myrrhidium'' de Candolle - 8 species
* subgenus ''Parvulipetala'' 3 sections
** section ''Isopetalum'' (Sweet) de Candolle - 1 species ('' Pelargonium cotyledonis'' (L.) L'Hér.)
** section ''Peristera'' de Candolle - 30 species
** section ''Reniformia'' (Knuth) Dreyer - 8 species
* subgenus ''Paucisignata'' 2 sections
** section ''Ciconium'' (Sweet) Harvey - 16 species
** section ''Subsucculentia'' J.J.A. van der Walt - 3 species
* subgenus ''Pelargonium'' 8 sections
** section ''Campylia'' (Lindley ex Sweet) de Candolle - 9 species
** section ''Cortusina'' (DC.) Harvey - 7 species
** section ''Hoarea'' (Sweet) de Candolle - 72 species
** section ''Ligularia'' (Sweet) Harvey - 10 species
** section ''Magnistipulacea'' Roeschenbl. & F. Albers Type: ''Pelargonium schlecteri'' Knuth - 2 subsections
*** subsection ''Magnistipulacea'' Roeschenbl. & F. Albers Type: ''Pelargonium schlecteri'' Knuth - 2 species (''P. schlecteri'' & '' P. luridum'')
*** subsection ''Schizopetala'' (Knuth) Roeschenbl. & F. Albers Type: ''Pelargonium caffrum'' (Eckl. & Zeyh.) Steudel - 3 species (''P. caffrum'', ''P. bowkeri'', ''P. schizopetalum'')
** section ''Otidia'' (Lindley ex Sweet) de Candolle - 14 species
** section ''Pelargonium'' L'Hér. - 34 species
** section ''Polyactium'' de Candolle - 2 subsections
*** subsection ''Caulescentia'' Knuth - 1 species (''Pelargonium gibbosum'')
*** subsection ''Polyactium'' de Candolle - 7 species

Subgenera

Subgenus ''Magnipetala'': Corresponds to clade C1, with 24 species. Perennial to short lived, spreading subshrubs, rarely herbaceous annuals. Petals five, but may be four, colour mainly white. Mainly winter rainfall region of South Africa, spreading into summer rainfall region. One species in northern Namibia and Botswana. Two species in East Africa and Ethiopia. Chromosomes x=11 and 9.

Subgenus ''Parvulipetala'': Corresponds to clade B, with 39-42 species. Perennials, partly annuals. Petals five and equal, colour white or pink to deep purplish red. Mainly South Africa, but also other southern hemisphere except South America. a few species in East Africa and Ethiopia. Chromosomes x=7-19.

Subgenus ''Paucisignata'': Corresponds to clade C2, with 25-27 species. Erect sometimes trailing shrubs or subshrubs, rarely geophytes or semi-geophytes. Petals five and equal, colour pink to red sometimes white. Summer rainfall region of South Africa, spreading into winter rainfall region and northern Namibia, with a few species in tropical Africa, Ethiopia, Somalia, Madagascar, the Arabian Peninsula and Asia Minor. Chromosomes x=mainly 9 or 10, but from 4-18.

Subgenus ''Pelargonium'': Corresponds to clade A, with 167 species. Frequently xerophytic deciduous perennials with many geophytes and succulent subshrubs, less frequently woody evergreen shrubs or annual herbs. Petals five, colour shades of pink to purple or yellow. Winter rainfall region of South Africa and adjacent Namibia, spreading to summer rainfall area, and two species in tropical Africa. Chromosomes x=11, may be 8-10.{{sfn, Roschenbleck et al, 2014

Species

{{main, List of Pelargonium species
''Pelargonium'' has around 280 species.{{r, powo{{cite journal, last1=Weng, first1=ML, last2=Ruhlman, first2=TA, last3=Gibby, first3=M, last4=Jansen, first4=RK, date=Sep 2012, title=Phylogeny, rate variation, and genome size evolution of Pelargonium (Geraniaceae), journal=Mol Phylogenet Evol, volume=64, issue=3, pages=654–70, doi=10.1016/j.ympev.2012.05.026 , pmid=22677167 Röschenbleck ''et al'' lists 281 taxa.{{sfn, Roschenbleck et al, 2014 There is considerable confusion as to which ''Pelargonium'' are true species, and which are cultivars or hybrids. The nomenclature has changed considerably since the first plants were introduced to Europe in the 17th century.

Distribution

''Pelargonium'' is a large genus within the family Geraniaceae, which has a worldwide distribution in temperate to subtropical zones with some 800 mostly herbaceous species.{{sfn, Roschenbleck et al, 2014 ''Pelargonium'' itself is native to southern Africa (including Namibia) and Australia. Southern Africa contains 90% of the genus, with only about 30 species found elsewhere, predominantly the East African rift valley (about 20 species) and southern Australia, including Tasmania.{{sfn, Roschenbleck et al, 2014 The remaining few species are found in southern Madagascar, Yemen, Iraq, Asia Minor, the north of New Zealand and isolated islands in the south Atlantic Ocean (Saint Helena and Tristan da Cunha) and Socotra in the Indian Ocean.{{sfn, Roschenbleck et al, 2014 The centre of diversity is in southwestern South Africa where rainfall is confined to the winter, unlike the rest of the country where rainfall is predominantly in the summer months.{{sfn, Roschenbleck et al, 2014 Most of the ''Pelargonium'' plants cultivated in Europe and North America have their origins in South Africa.{{cite web , last=Sayre , first=James K. , year=2003 , url=http://www.bottlebrushpress.com/scentedgeraniums.html , title=Scented Geraniums or Pelargoniums , publisher=Bottlebrushpress.com , url-status=dead , archive-url=https://web.archive.org/web/20110708085450/http://www.bottlebrushpress.com/scentedgeraniums.html , archive-date=2011-07-08

Ecology

''Pelargonium'' species are eaten by the caterpillars of some Lepidoptera species, including the noctuid moth angle shades, ''Phlogophora meticulosa''. The diurnal butterflies '' Cacyreus marshalli'' and '' C. tespis'' (Lycaenidae), native to southern Africa, also feed on ''Geranium'' and ''Pelargonium''. ''C. marshallii'' has been introduced to Europe and can develop into a pest on cultivated Pelargoniums. It has naturalised along the Mediterranean, but does not survive the winter in Westen Europe.

The Japanese beetle, an important agricultural insect pest, becomes rapidly paralyzed after consuming flower petals of the garden hybrids known as "zonal geraniums" (''P.'' × ''hortorum''). The phenomenon was first described in 1920, and subsequently confirmed. Research conducted by Dr. Christopher Ranger with the USDA Agricultural Research Service and other collaborating scientists have demonstrated the excitatory amino acid called quisqualic acid present within the flower petals is responsible for causing paralysis of the Japanese beetle. Quisqualic acid is thought to mimic L-glutamic acid, which is a neurotransmitter in the insect neuromuscular junction and mammalian central nervous system.

A study by the Laboratory of Apiculture & Social Insects group at the University of Sussex on the attractiveness of common garden plants to pollinators found that a cultivar of ''Pelargonium'' × ''hortorum'' was unattractive to pollinators in comparison to other selected garden plants such as '' Lavandula'' (lavender) and '' Origanum''.{{cite journal, title=Quantifying variation among garden plants in attractiveness to bees and other flower-visiting insects, journal=Functional Ecology, year=2013, doi=10.1111/1365-2435.12178, volume=28, issue=2, pages=364–374, last1=Garbuzov, first1=Mihail, last2=Ratnieks, first2=Francis L. W.

Pests and diseases

{{Main, List of geranium diseases, Pelargonium flower break virus, Pelargonium line pattern virus

The geranium bronze butterfly is a pest of ''Pelargonium'' species. The larvae of the geranium bronze bore into the stem of the host plant, causing the stem to typically turn black and die soon after. Geranium bronze are currently listed as an A2 quarantine pest by the European and Mediterranean Plant Protection Organization and can cause significant damage to ''Pelargonium'' species.

Cultivation

Various types of ''Pelargonium'' are regular participants in flower shows and competitive events, with numerous societies devoted exclusively to their cultivation. They are easy to propagate vegetatively from cuttings.{{cite book , title=RHS A-Z encyclopedia of garden plants , year=2008 , publisher=Dorling Kindersley , location=United Kingdom , isbn=978-1405332965 , page=1136 Zonal geraniums grow in U.S. Department of Agriculture hardiness zones 9 through 12. Zonal geraniums are basically tropical perennials. Although they are often grown as annuals, they may overwinter in zones as cool as zone 7.

Cultivation history

The first species of ''Pelargonium'' known to be cultivated was ''P. triste'', a native of South Africa. It was probably brought to the Botanical Garden in Leiden before 1600 on ships which had stopped at the Cape of Good Hope. In 1631, the English gardener John Tradescant the elder bought seeds from Rene Morin in Paris and introduced the plant to England. By 1724, '' P. inquinans'', '' P. odoratissimum'', '' P. peltatum'', '' P. vitifolium'', and '' P. zonale'' had been introduced to Europe.{{sfn, Taylor, 2014, lo
Pelargonium
}

Cultivars

There was little attempt at any rational grouping of ''Pelargonium'' cultivars, the growing of which was revived in the mid-twentieth century, and the origins of many if not most were lost in obscurity. In 1916 the American botanist Liberty Hyde Bailey (1858–1954) introduced two new terms for zonal and regal pelargoniums. Those pelargoniums which were largely derived from '' P. zonale'' he referred to as ''P.'' × ''hortorum'' (i.e. from the garden), while those from '' P. cucullatum'' he named ''P.'' × ''domesticum'' (i.e. from the home).{{sfn, Wilkinson, 2007, lo
p. 189
} In the late 1950s a list (the Spalding List) was produced in the United States, based on nursery listings and the 1897 list of Henri Dauthenay.{{sfn, Dauthenay, 1897 It described seven groups, listing each cultivar with the list of its originator, and in most cases a date. These were Species, Zonals, Variegated-Leaved, Domesticum (Regals), Ivy-Leaved, Scented-Leaved and Old. In the 1970s the British Pelargonium and Geranium Society produced a checklist and the Australian Geranium Society started to produce a register but it was not completed till its author, Jean Llewellyn's death in 1999. None of these were published. The most complete list in its time was the 2001 compilation by The Geraniaceae Group,{{sfn, Amadio, 2015 which included all cultivars up to 1959.{{sfn, Wilkinson, 2007, lo
Appendix 2: Horticultural Classification and Glossary
}

Registration of cultivars is the responsibility of the Pelargonium & Geranium Society (PAGS: formed in 2009 from the British Pelargonium and Geranium Society and the British and European Geranium Society){{sfn, PAGS, 2015, lo
About us
} which administers the International Register of Pelargonium Cultivars.{{sfn, PAGS, 2015, lo
International Register of Pelargonium Cultivars
} PAGS is the International Cultivar Registration Authority (ICRA) of the International Society for Horticultural Science for pelargoniums.{{sfn, ISHS, 2015, lo
ICRA">International Cultivar Registration Authority, ICRA
: Pelargonium and Geranium Society}

Cultivated pelargoniums are commonly divided into six groups{{sfn, RHS, 2015, lo
''Pelargonium'' (geranium)
} in addition to species pelargoniums and primary hybrids. The following list is ordered by position in the PAGS classification.{{sfn, PAGS, 2015, lo
Pelargonium Basics
} Abbreviations indicate Royal Horticultural Society usage.{{sfn, RHS, 2015, lo
Horticultural classification for ''Pelargonium'' L'Her. ex Aiton
}

* A. Zonal (Z)
* B. Ivy-leaved (I)
* C. Regal (R)
* D. Angel (A)
* E. Unique (U)
* F. Scented-leaved (Sc)
* G. Species
* H. Primary hybrids

Of these, A, U and Sc groups are sometimes lumped together as Species Derived (Sppd). This term implies that they are closely related to a species from which they were derived, and do not fit into the R, I or Z groups.{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
}

In addition to the primary groups, additional descriptors are used. The Royal Horticultural Society has created description codes. These include;{{sfn, RHS, 2015, lo
Horticultural classification for ''Pelargonium'' L'Her. ex Aiton
}

* Cactus (Ca)
* Coloured foliage (C)
* Decorative (Dec)
* Double (d)
* Dwarf (Dw)
* Dwarf Ivy-leaved (Dwl)
* Frutetorum (Fr)
* Miniature (Min)
* Miniature Ivy-leaved (MinI)
* Stellar (St)
* Tulip (T)
* Variegated (v)

These may then be combined to form the code, ''e.g.'' ''Pelargonium'' 'Chelsea Gem' (Z/d/v), indicating Zonal Double with variegated foliage. Crosses between groups are indicated with an ×, ''e.g.'' ''Pelargonium'' 'Hindoo' (R × U), indicating a Regal × Unique cross.

A. Zonal pelargoniums (''Pelargonium'' × ''hortorum'' Bailey)

These are known as zonal geraniums because many have zones or patterns in the center of the leaves, this is the contribution of the '' Pelargonium zonale'' parent. Common names include storksbill, fish or horseshoe geraniums.{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
} They are also referred to as ''Pelargonium'' × ''hortorum'' Bailey. Zonal pelargoniums are tetraploid, mostly derived from '' P. inquinans'' and '' P. zonale'', together with ''P. scandens'' and ''P. frutetorum''.{{sfn, RHS, 2015, lo
''Pelargonium'' (geranium)
}

Zonal pelargoniums are mostly bush-type plants with succulent stems grown for the beauty of their flowers, traditionally red, salmon, violet, white or pink. The scarlet colouring is attributed to the contribution of ''P. inquinans''.{{sfn, Taylor, 2014, lo
Pelargonium
} Flowers may be double or single. They are the pelargoniums most often confused with genus ''Geranium'', particularly in summer bedding arrangements. This incorrect nomenclature is widely used in horticulture, particularly in North America.{{sfn, Taylor, 2014, lo
Pelargonium
}

Zonals include a variety of plant types along with genetic hybrids such as hybrid ivy-leaved varieties that display little or no ivy leaf characteristics (the Deacons varieties), or the Stellar varieties. Hybrid zonals are crosses between zonals and either a species or species-derived pelargonium.{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
} There are hundreds of zonal cultivars available for sale, and like other cultivars are sold in series such as 'Rocky Mountain', each of which is named after its predominant colour, ''e.g.'' 'Rocky Mountain Orange', 'White', 'Dark Red', ''etc''.

*(i) Basic plants – Mature plants with foliage normally exceeding {{convert, 180, mm, in, 0, abbr=on in height above the rim of the pot. For exhibition these should be grown in a pot exceeding {{convert, 120, mm, in, frac=4, abbr=on in diameter but not normally exceeding {{convert, 165, mm, in, frac=2, abbr=on.
*(ii) Dwarf plants – Smaller than basic. Mature plants with foliage more than {{convert, 125, mm, in, 0, abbr=on above the rim of the pot, but not normally more than {{convert, 180, mm, in, 0, abbr=on. For exhibition should be grown in a pot exceeding {{convert, 90, mm, in, frac=2, abbr=on but not exceeding {{convert, 120, mm, in, frac=4, abbr=on. They should not exceed 200 mm in height, grown in an 11 cm pot.{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
}
*(iii) Miniature plants – Slowly growing pelargoniums. Mature plants with foliage normally less than {{convert, 125, mm, in, 0, abbr=on above the rim of the pot. For exhibition should be grown in a pot not exceeding {{convert, 90, mm, in, frac=2, abbr=on. They should not exceed 125 mm in height, grown in a 9 cm pot.{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
}
*(iv) Micro-miniature plants – Smaller and more slowly growing than miniature pelargoniums. Mature plants with foliage normally less than {{convert, 100, mm, in, 0, abbr=on above the rim of the pot. They should not exceed 75 mm in height, grown in a 6 cm pot.{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
} Usually no separate classes for these in exhibition and will therefore normally be shown as Miniature Zonals.
*(v) Deacon varieties –Genetic hybrid similar to a large Dwarf. For exhibition (when shown in a separate class), usually grown in a pot not exceeding {{convert, 125, mm, in, 0, abbr=on, otherwise as for Dwarf Zonals.
*(vi) Stellar varieties – A relatively modern genetic hybrid originating from the work done by the Australian hybridiser Ted Both in the late 1950s and 1960s from crosses between Australian species and Zonal types. Easily identifiable by their distinctive half-star-shaped leaves and slim-petalled blooms which create an impression of being star shaped (or five fingered). Single varieties tend to have larger elongated triangular petals whereas doubles tend to have thin feathered petals that are tightly packed together. For exhibition purposes there is a separate class for 'Stellar' varieties, but being Zonals could be shown in an open class for Basic, Dwarf or Miniature Zonals (unless otherwise stated). Also known as "The Five-fingered Geraniums", "Staphysagroides", "Both’s Staphs", "Both’s Hybrid Staphs", "Fingered Flowers" and "Bodey’s Formosum Hybrids".{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
}

Fancy-leaf zonal pelargoniums – besides having green leaves with or without zoning, this group also have variable coloured foliage{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
} that is sometimes used in classifying for exhibition purposes, ''e.g.'' ‘Bicolour’, ‘Tricolour’, ‘Bronze’ or ‘Gold’. Other foliage types are: ‘Black’ or ‘Butterfly’. There are an increasing number of these plants with showy blooms;

*(a) Bicolour – includes those with white or cream veined leaves or those with two distinct colours with clearly defined edges, other than the basic zone.
*(b) Tricolour – (May be Silver Tricolour (usually called a Silver Leaf) or a Gold Tricolour).
**(i) Gold Tricolour – Leaves of many colours including red and gold, but usually with clearly defined edges of golden yellow and having a leaf zone, usually red or bronze, that overlays two or more of the other distinct leaf colours, so that the zone itself appears as two or more distinct colours.
**(ii) Silver Tricolour or Silver Leaf – These tend to resemble a normal bi-colour leaf plant with two distinct colours usually of green and pale cream or white; the third colour is usually made up of bronze zoning. When this zoning overlays the green part of the leaf it is deemed to represent a silver colour.
*(c) Bronze Leaved – Leaves of Green or Golden/Green with a heavy bronze or chestnut coloured centre zone which is known as a medallion. For exhibition purposes, when exhibited in specific ‘Bronze’ Leaf class – Must have over 50% of leaf surface bronze coloured. The dwarf plant ‘Overchurch’ which has a heavy bronze medallion.
*(d) Gold Leaved – Leaves coloured golden/yellow or green/yellow but not showing a tendency to green. For exhibition purposes, when exhibited in specific ‘Gold’ Leaf class – Must have over 50% of leaf surface gold coloured.
*(e) Black Leaved – Leaves coloured black, purple-black or with distinct large dark zones or centre markings on green.
*(f) Butterfly Leaved – Leaves with a butterfly marking of distinct tone or hue in centre of leaf. This can be encompassed in many of the coloured leaf varieties.

Zonal pelargoniums have many flower types, as follows:{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
}

*(a) Single flowered (S) – each flower pip normally having no more than five petals. This is the standard flower set for all Pelargoniums.
*(b) Semi-double flowered (SD) – each flower pip normally having between six and nine petals.
*(c) Double flowered (D)– each flower pip composed of more than nine petals (i.e. double the standard flower set) but not ‘hearted’ like the bud of a rose, ''e.g.'' the dwarf ‘Dovepoint’ which has full double blooms.
*(d) Rosebud (or noisette) flowered – each bloom fully double and ‘hearted’. The middle petals are so numerous that they remain unopened like the bud of a rose.{{sfn, PAGS, 2015, lo
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*(e) Tulip flowered – having semi-double blooms that never fully open. The large cup shaped petals open just sufficiently to resemble a miniature tulip.
*(f) Bird's-egg group – having blooms with petals that have spots in a darker shade than the base colour, like many birds eggs.{{sfn, PAGS, 2015, lo
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*(g) Speckled flowered group – having petals that are marked with splashes and flecks of another colour, ''e.g.'' ‘Vectis Embers’.
*(h) Quilled (or cactus-flowered group, or poinsettia in USA) – having petals twisted and furled like a quill.{{sfn, PAGS, 2015, lo
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“Zonquil” pelargoniums result from a cross between Zonal pelargonium cultivars and ''P. quinquelobatum''.{{sfn, PAGS, 2015, lo
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B. Ivy-leaved pelargoniums (derived from ''Pelargonium peltatum'')

Also known as "ivy geraniums".{{sfn, PAGS, 2015, lo
Horticultural symbols and terms
}Usually of lax growth (trailing), mainly due to the long thin stems, with thick, waxy ivy-shaped stiff fleshy evergreen leaves developed by the species ''P. peltatum'' to retain moisture during periods of drought. Much used for hanging pots, tubs and basket cultivation. In the UK the bulbous double-headed types are preferred whilst on the European continent the balcon single types for large-scale hanging floral displays are favoured. Ivy-leaved pelargoniums embrace all such growth size types including small-leaved varieties and genetic hybrid crosses, which display little or no zonal characteristics. May have bicolour leaves and may have flowers that are single, double or rosette. Ivy pelargoniums are often sold as series such as 'Great Balls of Fire', in a variety of colours such as 'Great Balls of Fire Burgundy'.

Additional descriptive terms include;{{sfn, PAGS, 2015, lo
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* Hybrid Ivy — the result of ivy × zonal crosses, but still more closely resemble ivy-leaved pelargoniums.
* Fancy leaf — leaves with marked color variation, together with or other than green.
* Miniature — miniature leaves and flowers, stems with short nodes, and compact growth. ''e.g.'' 'Sugar Baby' listed as Dwarf Ivy (DwI) by RHS.{{sfn, RHS, 2015, lo
Horticultural classification for ''Pelargonium'' L'Her. ex Aiton
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C. Regal pelargoniums (''Pelargonium'' × ''domesticum'' Bailey)

These are large bush-type floriferous