Ixerba brexioides

Ixerba brexioides
	Ixerba brexioides , illustration
Systematics
	Rosids
	Eurosiden II
Order :	Crossosomatales
Family :	Strasburgeriaceae
Genre :	Ixerba
Type :	Ixerba brexioides
Scientific name of the genus
	Ixerba
	A. Cunn.
Scientific name of the species
	Ixerba brexioides
	A. Cunn.

inflorescence

Ixerba is an evergreen tree in New Zealand , which alone the plant genus of Ixerba within the family strasburgeriaceae forms. In New Zealand the species is called “Tāwhiri” or “Tawari” and the flowers are called “whakou”.

features

It is an evergreen tree with a spreading crown that can grow up to ten meters high. The trunk reaches a diameter of 0.2 to 0.4 meters. The bark is dark to gray-brown. The branches, leaves and inflorescences are lightly hairy when young.

The leaves are pseudo whorls . They are without pages. The leaf stalks are two inches long and fleshy. The leaves are yellow-green to dark green on the upper side and lighter on the underside. Young leaves are often reddish. They are somewhat fleshy, very leathery, 60 to 160 millimeters long and 10 to 40 millimeters wide, lanceolate to elliptical with a pointed apex. The leaf margin is clearly and roughly serrated. There is a small gland at the tip of each tooth.

The inflorescences are terminal, consist of five to ten flowers that form an umbrella-shaped spike . The flowers are white, relatively large (25 to 35 millimeters in diameter) with five sepals and five petals each , ten stamens with thick connective elements. The pollen is 4- to 5-colporat. The ovary is striking, consists of five fused carpels and graduates into the pen over. The stylus is heavily grooved and spirally twisted at the tip. A lobed nectarium sits at the base of the ovary. The vascular bundles in the flower base are densely packed. Flowering time is October and November.

In the pointed capsule fruit there are a few shiny black seeds with a conspicuous orange-red aril . Fruit ripe from November to January. The seeds may be spread by pigeons.

The species lacks non-hydrolyzable tannins . The chromosome number is n = 25.

distribution

Ixerba brexioides is endemic to the North Island of New Zealand . The area is limited to the north of the North Island from Waitomo , Paeroa Range and Te Urewera north to the hills south of Kaitaia .

The tree grows in kauri forests and montane cloud forests. It prefers shady and sheltered places, often near flowing water and on constantly moist soil. The species is rather rare and only occurs in larger numbers in some places. But it is not endangered.

The species is difficult to cultivate. It is believed that it needs a mycorrhiza to grow. If planted with Griselinia littoralis , it should grow well.

Systematics

Within the Crossosomatales , Ixerba is the sister taxon of Strasburgeria . Both groups have the following features in common: at least in the flowers cells with thickened mucous inner tangential walls; needle-shaped crystals; spiral leaves with a glandular-serrated margin; large flowers with spiral calyx; flat filaments; Anthers over three millimeters long; Carpel sessile, epitropic with a long hollow stylus that is retained on the fruit; Base chromosome number of 25.

Cronquist had 1,981 Ixerba in the Grossulariaceae found Airy Shaw in the Brexiaceae and Tachtadschjan 1997 in the Rosidae-Brexiales. The Angiosperm Phylogeny Group has placed the genus together with Strasburgeria in the Strasburgeriaceae family since 2009 .

Sources and further information

literature

Jason A. Koontz, Douglas E. Soltis: DNA sequence data reveal polyphyly of Brexioideae (Brexiaceae; Saxifragaceae sensu lato). In: Plant Systematics and Evolution. Vol. 219, No. 3/4, 1999, ISSN 0378-2697 , pp. 199-208, doi : 10.1007 / BF00985579 , (not viewed).
Merran L. Matthews, Peter K. Endress: Comparative floral structure and systematics in Crossosomatales (Crossosomataceae, Stachyuraceae, Staphyleaceae, Aphloiaceae, Geissolomataceae, Ixerbaceae, Strasburgeriaceae). In: Botanical Journal of the Linnean Society. Vol. 147, No. 1, 2005, ISSN 0024-4074 , pp. 1-46, doi : 10.1111 / j.1095-8339.2005.00347.x , (not consulted).
Rajni N. Patel: Wood Anatomy of the Dicotyledons Indegenous to New Zealand. 2. Escalloniaceae. In: New Zealand Journal of Botany. Vol. 11, No. 3, 1973, ISSN 0028-825X , pp. 421-434, doi : 10.1080 / 0028825X.1973.10430292 .

Web links

Commons : Ixerba brexioides - collection of images, videos and audio files

Ixerba brexioides . New Zealand Plant Conservation Network, archived from the original onMay 28, 2007; accessed on August 24, 2014(English, original website no longer available).
Ixerbaceae on the APG website
Family Ixerbaceae GRISEBACH. schoepke.de, accessed on August 24, 2014 .
Fruit and seeds
IXERBACEAE Ixerba brexioides . Inside Wood - North Carolina State University,accessed August 24, 2014.

Individual evidence

^ W. Mary McEwen: The Food of the New Zealand Pigeon (Hemiphaga novaesellandia novaeseelandia). In: New Zealand Journal of Ecology. Vol. 1, 1978, ISSN 0110-6465 , pp. 99-108, (PDF; 266 kB) .
↑ Ixerba brexioides. ( Memento of December 15, 2007 in the Internet Archive ) In: NZ Plant Conservation Network.
↑ Angiosperm Phylogeny Group : An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. In: Botanical Journal of the Linnean Society. Vol. 161, No. 2, 2009, ISSN 0024-4074 , pp. 105-121, doi : 10.1111 / j.1095-8339.2009.00996.x .

[1] W. Mary McEwen: The Food of the New Zealand Pigeon (Hemiphaga novaesellandia novaeseelandia). In: New Zealand Journal of Ecology. Vol. 1, 1978, ISSN 0110-6465 , pp. 99-108, (PDF; 266 kB) .

[2] Ixerba brexioides. ( Memento of December 15, 2007 in the Internet Archive ) In: NZ Plant Conservation Network.

[APGIII-3] Angiosperm Phylogeny Group : An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. In: Botanical Journal of the Linnean Society. Vol. 161, No. 2, 2009, ISSN 0024-4074 , pp. 105-121, doi : 10.1111 / j.1095-8339.2009.00996.x .