Пеларгония: Түрлер, сипаттамалары және классификациясы

Genus of plants

Pelargonium (,/p//ɛ//l//ɑr/'/ɡ//oʊ//n//i//.//ə//m/) 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.

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).

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.

All subdivision classifications had depended primarily on morphological differences till the era of phylogenetic analyses (Price and Palmer 1993). However phylogenetic analysis shows only three distinct clades, labelled A, B and C. Röschenbleck et al lists 281 taxa. 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.

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.

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.

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. 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.

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.

Angel pelargoniums are similar to Regal pelargoniums but more closely resemble P. crispum in leaf shape and growth habit. The majority of Angel cultivars originate from a cross between P. crispum and a Regal variety in the early part of the 20th century. Angels have grown in popularity in the last 30 years or so due mainly to an explosion of new varieties being released by specialist nurseries resulting from the work done by dedicated amateur hybridisers. These hybrisers have managed to obtain many new flower colour breaks and tighter growth habits resulting in plants suitable for all sorts of situations. Angels basically have the appearance of a small Regal with small serrated leaves and much smaller flowers and are more compact and bushy. The group extends to include similar small leaved and flowered types but usually with P. crispum in their parentage. They are mostly upright bush type plants but there are some lax varieties that can be used for basket or hanging pot cultivation. Often called "pansy faced" in the US. Some varieties have bicolour foliage. Other terms include ‘Langley Smith Hybrids’.