Kadua

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Kadua
Kadua affinis

Kadua affinis

Systematics
Euasterids I
Order : Enzianartige (Gentianales)
Family : Red family (Rubiaceae)
Subfamily : Rubioideae
Tribe : Spermacoceae
Genre : Kadua
Scientific name
Kadua
Cham. & Schltdl.

Kadua is a plant genus in the family of the redness plants (Rubiaceae). The 30 or so species are found on some Pacific islands.

description

Flowers of Kadua fluviatilis

Vegetative characteristics

The Kadua species grow as perennial herbaceous or succulent plants, upright to climbing shrubs or lianas , and occasionally as small to medium-sized trees . The shoots can be bald to sparsely hairy. Some species give off an unpleasant odor when injured.

The constantly against arranged on the branches leaves are divided in most species in petiole and leaf blade. In some species, however, the petiole is missing. The thin, leathery to paper-like leaf blades are simple and have entire spreading margins. The interpetiolaren, occasionally intrapetiolaren, triangular stipules may be fused with the petioles and then form a short sheath . They have entire, toothed or comb-like leaf margins and a spiky, pointed tip.

Generative characteristics

The Kadua species can be hermaphroditic, occasionally monoecious ( monoecious ) separate sexes. The flowers stand individually in reduced umbels or stand together in terminal or lateral, zymous panicle or panicle-like inflorescences , which are usually triply branched.

The mostly hermaphroditic, more rarely unisexual flowers are radial symmetry . The white to greenish-white, pink to violet or violet-greenish, mostly fleshy petals are plate-shaped, but occasionally also bell-like or jug-like fused together and the crown ends in four or five corolla lobes. The petals of a flower can be of different sizes. The crown lobes have appendages at their tips. The stamens are inserted in the middle or close to the base of the corolla tube. The anthers are sessile or sit on short stamens . Two to four carpels are an ovary fused, each of the carpels a few to numerous ovule having. The stylus, which is lobed two to four times, is cylindrical to thread-shaped. There is a scar .

The capsule fruits are mostly dry, rarely fleshy. The endocarp is more or less lignified while the mostly thin, rarely thick mesocarp is fissured almost to the base. The mesocarp is rarely surrounded by a thick, fleshy, juicy hypanthium and then appears berry-like . Each of the fruits contains few to numerous, richly shaped seeds. In some species the seeds have a wing with a hilum on the wing edge.

Chromosome number

The number of chromosomes can be 2n = 72 or 2n = c. 100.

distribution

The distribution area of the Kadua species extends from Tuvalu , Tokelau and the Cook Islands through the Line Islands , French Polynesia and the Pitcairn Islands to Hawaii . Hawaii is the main distribution center of the genus Kadua , as there is a great diversity of species.

Systematics

Flowers of Kadua formosa
Flowers of Kadua lichtlei
Ripe capsules of Kadua littoralis
Kadua parvula

The genus Kadua was established in Linnaea , Volume 4, Page 157 in 1829 by Adelbert von Chamisso and Diederich Franz Leonhard von Schlechtendal . Synonyms for Kadua Cham. & Schltdl. are: Wiegmannia Meyen and Gouldia A. Gray .

The genus Kadua belongs to the tribe Spermacoceae in the subfamily Rubioideae within the Rubiaceae family .

There are about 30 species of Kadua :

Individual evidence

  1. ↑ a b c d e f g h Kadua. In: Flora of the Hawaiian Islands. www.botany.si.edu/pacificislandbiodiversity/hawaiianflora, accessed on November 15, 2016 (English).
  2. ^ Kadua at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed November 15, 2016.
  3. ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af Rafaël Govaerts (ed.): Kadua. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved November 4, 2018.

Web links

Commons : Kadua  - collection of images, videos and audio files