Selenia (genus)

from Wikipedia, the free encyclopedia
Selenia
Systematics
Rosids
Eurosiden II
Order : Cruciferous (Brassicales)
Family : Cruciferous vegetables (Brassicaceae)
Tribe : Cardamineae
Genre : Selenia
Scientific name
Selenia
Nutt.

Selenia forms a genus of plants inthe cruciferous family (Brassicaceae). The five species are found in the United States and Mexico .

description

Appearance and leaves

The Selenia species grow as annual , sometimes winter-annual herbaceous plants . All parts of the plant are bare. The rarely missing stems are upright to creeping and unbranched or branched in the upper areas.

The leaves are basal or basal in rosettes and are also distributed on the stem. The stalked basal leaves are single or double (or triple) pinnate ; the leaf margin of the terminal section is entire or toothed. The seated or barely stalked and non-eyed stem leaves resemble the basal leaves.

Inflorescence and flowers

The traubigen inflorescences with straight inflorescence rachis are continuous with the supporting sheets provided. The slender, sparse to ascending flower / fruit stalks elongate considerably until the fruit is ripe.

The hermaphroditic flowers are radial symmetry and four-fold. The four sometimes durable, yellowish sepals are erect to spread and oblong-linear or oblong-lanceolate. The two lateral sepals are slightly sagged at their base. The four yellow and nailed petals are spatulate to broadly obovate with a rounded or edged, rarely blunt tip. There are two circles with a total of six stamens . The outer circle contains two short, the inner circle four long stamens. The stamens are not widened at their base. The anthers are linear, ovoid or oblong and rarely arrow-shaped. The individual sap glands flow together. Depending ovary are 8-44 ovules present. The irregular stylus , sometimes flattened at the base, with a length of 1 to 12 millimeters, ends in a cephalic scar .

Fruits and seeds

The fruits are smooth, broadly septate, seated or short-stalked pods or pods with usually elongated, elliptical, rounded or spherical, rarely obovate shape. The thin-skinned to leathery, blister- shaped valves in Selenia grandis are veined indistinctly to clearly reticulate if the central nerve is missing. The placental frame is round or flattened. The septum is fully developed or perforated.

The seeds , standing in one or two rows, are circular, laterally flattened and winged throughout. The coarse, net-like seed coat does not become slimy when wet. In the embryo , the position of the root system in comparison to the cotyledons is pleurorrhizal or lateral rooted (accumbent).

Chromosome equipment

The basic chromosome number is x = 7, 12, 13.

Occurrence

The five or so Selenia species inhabit central and southwestern regions of the USA and northeastern Mexico.

Systematics

The first description of the species Selenia was made in 1825 by Thomas Nuttall in the Journal of the Academy of Natural Sciences of Philadelphia , Volume 5, page 132, Table sixth

The genus Selenia belongs to the tribe Cardamineae within the family Brassicaceae .

There are five types of Selenia :

swell

literature

  • Ihsan A. Al-Shehbaz: Selenia . In: Flora of North America Editorial Committee (Ed.): Flora of North America . Magnoliophyta: Salicaceae to Brassicaceae . Volume 7. Oxford University Press, New York a. a. 2010, ISBN 978-0-19-531822-7 , pp. 506 (English, Selenia - online - online with the same text as the printed work). (Section Description and Distribution)

Individual evidence

  1. ^ GRIN - Taxonomy for Plants. Gender: Selenia Nutt. Germplasm Resources Information Network, accessed September 1, 2011 .
  2. ^ The Plant List. A working list of all plant species. Retrieved August 25, 2011 (assessment of which species might be valid).

Web links