Hydrangeaceae

Hydrangea ( Hydrangea macrophylla)

The hydrangea plants ( Hydrangeaceae ) are a family of plants in the order of the dogwood -like ( Cornales ). It includes 17 genera with about 220 species, most of which are native to the northern temperate latitudes and the subtropics. Some species of the genus Carpenteria, Deutzia, Hydrangea and Philadelphus are ornamental plants, the best known is probably the Hydrangea ( Hydrangea macrophylla).

Description

Appearance and leaves

The types of hydrangea plants are evergreen or deciduous shrubs, vines, subshrubs or rarely perennial herbaceous plants that grow from a woody rhizome. The shoot axes are self- erect to ascending, sometimes climbing or hanging. Woody species exhibit 's peeling in strips or sheets bark.

The almost always opposite, rarely alternate or whorled arranged leaves are conspicuous to barely recognizable stalked. The simple leaf blade often has a lobed, often a smooth, toothed or serrated edge. The Blattnervatur is usually pinnately, but at Fendlera, Fendlerella, Philadelphus and Whipplea it is acrodrom ( = the side nerves run parallel to the blade edge for a while and then in the direction of blade tip ). Stipules absent.

Inflorescences and flowers

The numerous and either small or large and few flowers are in terminal or lateral, zymösen, occasionally in schirmrispigen, thyrsoiden or paniculate inflorescences together. There may be bracts ( bracts = bract).

Usually the flowers are hermaphroditic and these are all radial symmetry. Rarely the flowers unisexual and then the species dioecious getrenntgeschlechtig ( dioecious ). In some species there are sterile ( infertile ), zygomorphe flowers whose sepals are enlarged striking and strong. It is a flower cup ( hypanthium ) available. In the conjoined or free at their base four to twelve sepals cover the buds is either klappig or dachziegelig. The four to twelve petals are either at its base or completely fused into a closed cap ( calyptra ).

It is usually a nectar discus available. Four to 200 stamens are arranged in one, two or multiple loops. The free or fused at their base stamens are flat and either linear awl - or thread-like, forked ends may occur. The anthers are connected at their approach with the stamens. The two to twelve carpels are fused to a syncarp, partially or completely inferior ovary.

Fruit and seeds

The fruits of two to 350 seeds are containing septizidale or lokulizidale capsule fruits or berries rare. The seeds are more than 10 millimeters in size.

Dissemination and paleobotany

The distribution of Hydrangeaceae ranges from temperate latitudes to the subtropics. The species occur in the New World, in Eurasia and the Pacific Islands. Their main distribution they have in the northern temperate latitudes ( Holarctic ) and in the subtropics. In the Neotropics, they occur from Mexico to Chile, especially in the Andes. In North America, there are nine genera with about 25 species.

About Hydrangeaceae are good paleobotanical reports. Fossils date back to the upper Cretaceous and most finds there from the Tertiary.

System

The Hydrangeaceae family was erected in 1829 by Barthélemy Charles Joseph Dumortier in analysis of Familles de Plantes, pp. 36 and 38. Synonyms for Hydrangeaceae Dumort. are Hortensiaceae Martynov, Kirengeshomaceae Nakai and Philadelphaceae Martynov.

The Hydrangeaceae have been eingeorndnet as a family with woody species near the family Saxifragaceae. Phylogenetic analyzes of the 21st century, Hydrangeaceae in the order of Cornales as a sister group to the family of Loasaceae.

The hydrangea plants ( Hydrangeaceae ) family comprises about 17 genera with about 220 species and is divided into two subfamilies, the subfamily Hydrangeoideae turn into two tribes.

• Subfamily Jamesioideae Hufford: Fendlera Engelm. & A. Gray: With two to five species of the southwestern United States to northern Mexico.
• Jamesia Torr. & A. Gray ( Syn: Edwinia A.Heller ): With about two types of the southwestern United States to northern Mexico.

• Tribus Philadelpheae: With six genera: Carpenteria Torr. The only kind: Carpenteria californica Torr. This is endemic in California only in Fresno County.

• Whipplea modesta Torr. It occurs only in the western United States.

• Broussaisia ​​Gaudich. With the only kind: Broussaisia ​​arguta Gaudich. It occurs in Hawaii.

• Platycrater Siebold & Zucc arguta. It occurs in temperate warm China and Japan.

Evidence

• Craig C. Freeman: Hydrangeaceae prerelease version of 2010 not yet published Volume 12, Flora of North America, Provisional Publication of the Flora of North America Association - Full text PDF file. (Section Description, distribution and systematics)
• The Hydrangeaceae in APWebsite family. (Section Description, distribution and systematics)
• L. Hufford: Hydrangeaceae. In: Klaus Kubitzki (ed.): The Families and Genera of Vascular Plants - Volume VI - Flowering Plants - Dicotyledons - Celastrales, Oxalidales, Rosales, Cornales, Ericales, 2004, pp. 202-215, ISBN 978-3-540 - 06512-8 ( section distribution and systematics)