Cyanea (genus of plants)

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Cyanea
Cyanea hardyi

Cyanea hardyi

Systematics
Asterids
Euasterids II
Order : Astern-like (Asterales)
Family : Bellflower family (Campanulaceae)
Subfamily : Lobelia family (Lobelioideae)
Genre : Cyanea
Scientific name
Cyanea
Gaudich.

Cyanea is a genus of plants from the subfamily of the lobelia family (Lobelioideae) within the family of the bellflower family (Campanulaceae). The approximately 80 species are only native to the Hawaiian Islands. Their habitat are dense semi-arid or damp forests.

description

Zygomorphic flowers of Cyanea truncata
Habit , thorny leaves and trunk of Cyanea asplenifolia

The genus Cyanea is morphologically diverse.

Vegetative characteristics

Some species, such as Cyanea stichtophylla , grow as shrubs , while other species, such as Cyanea leptostegia , are trees that reach heights of up to 13 meters. They rarely grow as lianas or epiphytes .

The young Cyanea plants form thorn-like structures on the trunk and leaves, which they lose when they are fully grown. The purpose of these thorns has long remained a mystery. Some authors suggest that they were developed as a defense mechanism against the moa nalos , large Hawaiian ducks that became extinct before the arrival of Europeans.

The shape of the leaf blades is very different depending on the species.

Generative characteristics

The hermaphrodite flowers are zygomorphic and five-fold with a double flower envelope . The corolla is two or one lipped.

The berries are yellow, orange or purple in color when ripe.

The number of chromosomes is 2n = 28.

Danger

Cyanea is one of the most extinct and endangered plant species in the Hawaiian Islands. The IUCN lists ten species and one subspecies as extinct. 32 other taxa are considered to be critically endangered or endangered.

The reasons for the rarity are the destruction of vegetation by fire and overgrazing as well as displacement by invasive plant species .

Habit , thorny leaves and trunk of Cyanea duvalliorum
Habit and leaves of Cyanea elliptica
Fruits of Cyanea hirtella
Foliage leaves and ripe fruits of Cyanea profuga
Habit of an older specimen of Cyanea superba with leaves

Systematics

The genus Cyanea was founded in 1829 by Charles Gaudichaud-Beaupré in Voyage autour du Monde, entrepris par Ordre du Roi, ... éxécuté sur les Corvettes de SM ″ l'Uranie ″ et ″ la Physicienne ″, pendant les années 1817, 1818, 1819 et 1820 ... Botanique , p. 457. Type species is Cyanea grimesiana Gaudich.

Based on phylogenetic studies based on molecular data, Thomas G. Lammers divided the genus Rollandia Gaudich. into the genus Cyanea , which thereby becomes monophyletic . Another synonym for Cyanea Gaudich. is Kittelia Rchb.

Cyanea belongs to the subfamily Lobelioideae within the Campanulaceae family .

About 80 species of Cyanea are known; here with details of the islands of the Hawaii group:

literature

  • Warren L. Wagner , Derral R. Herbst, SH Sohmer: Manual of the Flowering Plants of Hawai'i . Vol. 1. In: University of Hawai'i Press , 1999.
  • Thomas G. Lammers, Thomas J. Givnish, Kenneth J. Sytsma: Merger of the Endemic Hawaiian Genera Cyanea and Rollandia (Campanulaceae: Lobelioideae). In: Novon , Volume 3, Issue 4, 1993, pp. 437-441.
  • Thomas J. Givnish, Kenneth J. Sytsma, JF Smith, WJ Hahn: Thorn-like prickles and heterophylly in Cyanea: Adaptations to extinct avian browsers on Hawaii? In: Proc. Natl. Acad. Sci. USA , Volume 91, Issue 7, March 29, 1994, pp. 2810–2814, PMC 43460 (free full text)

Individual evidence

  1. ↑ Thomas J. Givnish, Kenneth J. Sytsma, JF Smith, WJ Hahn: Thorn-like prickles and heterophylly in Cyanea: Adaptations to extinct avian browsers on Hawaii? In: Proc. Natl. Acad. Sci. USA , Volume 91, Issue 7, March 29, 1994, pp. 2810-2814, PMC 43460 (free full text).
  2. ^ Cyanea at Tropicos.org. Missouri Botanical Garden, St. Louis
  3. ^ A b Cyanea in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
  4. ↑ Overview of the Cyanea species - entry Cyanea in the Genus search field in Hawaiian flora .
  5. ↑ a b c d e f g h i j k l m n o p q r s t u v Rafaël Govaerts (Ed.): Cyanea. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved February 13, 2018.

Supplementary literature

  • Thomas G. Lammers: Five new species of the endemic Hawaiian genus Cyanea (Campanulaceae: Lobelioideae). In: Novon , Volume 14, 2004, pp. 84-101.
  • Craig C. Buss, Thomas G. Lammers, Robert R. Wise: Seed coat morphology and its systematic implications in Cyanea and other genera of Lobelioideae (Campanulaceae) , In: American Journal of Botany , Volume 88, 2001, pp. 1301-1308 . Full text online.
  • Thomas J. Givnish, Kenneth J. Sytsma, TB Patterson, JR Hapeman: Comparison of patterns of geographic speciation and adaptive radiation in Cyanea and Clermontia (Campanulaceae) based on a cladistic analysis of DNA sequence and restriction-site data. In: American Journal of Botany , Volume 83, 6, Supplement, 1996, p. 159.
  • Thomas J. Givnish, Kenneth J. Sytsma, JF Smith, WJ Hahn: Molecular evolution, adaptive radiation, and geographic speciation in Cyanea (Campanulaceae, Lobelioideae). In: WL Wagner, VA Funk (ed.): Hawaiian biogeography: evolution on a hot spot archipelago , pp. 288–337. Smithsonian Institution Press, Washington, DC, USA, 1995.

Web links

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