Grayia (plant)

Grayia spinosa

Grayia is a plant genus of the subfamily Chenopodioideae in the family of Amaranthaceae ( Amaranthaceae ). The four shrubby species occur in dry areas of the western United States, where they are under the trivial name " siltbush " and " hopsage " known.

• 4.1 Notes and references

Description

Appearance and leaves

The Grayia species are subshrubs or shrubs and reach stature heights of 15 to 150 centimeters. The woody stem axis grow erect or ascending, and are highly branched. The bark of old branches is gray-brown. Young branches are ribbed or striated, densely hairy, but verkahlen later. The side branches may end in thorny spikes. In the leaf axils are clearly protruding, almost spherical buds.

The change-constant leaves are sessile or narrowed slightly stalk -like at the base of the leaf. The green or gray, fleshy or leathery leaf blades are elliptical, with a length from 6 to 80 millimeters and a width of 1.5 to 42 mm, ovate, obovate, spatulate or linear-lanceolate. The leaves have a protruding midrib and a smooth margin. Especially in the area of the blade tip, the leaves are often hairy with simple or branched trichomes. The leaf anatomy corresponds to the " normal" (non - ring ) type of C3 plants.

Inflorescences and flowers

The Grayia species are dioecious ( dioecious ) or monoecious ( monoecious ) getrenntgeschlechtig. In axillary or terminal, scheinährigenn or panicled, interrupted inflorescences, the male flowers are entangled together or separately, the female flowers. The male flowers (without bracts ) have a perianth of four to five membranous, connected to the middle tepals 1 to 1.8 millimeters in length with hood -like tip. Before the tepals are four to five stamens which spring from a discus. The anthers do not protrude from the flower. The female flowers are sitting between two Down (Roll Brakteolen ), they have no perianth and consist of only one ovary with two filiform, prominent scars.

The Grayia - species bloom in their native range from March to June.

Fruit and seeds

At the time the fruit enveloping bracts grow up to 4 to 15 millimeters in length and width. You are folded along the midrib and connected almost to the top, which is characteristic for the genus Grayia. Their shape is round, broadly elliptical or heart-shaped, mostly entire, sometimes wavy or enlarged to two wings. Their surface can be flat or ribbed, glabrous or hairy. The first yellowish - green or cream colored Brakteolen stain for fruit ripening reddish or pink. The ripe fruit that remains enclosed by the continue reading, does not fall off. It is spherical in shape, obovate or laterally compressed lenticular, their membranous pericarp is free or only loosely adheres to the seeds. The vertical or horizontal standing seed has a brown or yellowish-brown, thin and membranous seed coat. The annular surrounds the embryo abundant, floury endosperm.

Sets of chromosomes

As chromosome numbers are 2n = 18 arizonica for the diploid Grayia and Grayia brandegeei and 2n = 36 reported for the tetraploid Grayia spinosa and Grayia plummeri.

Occurrence

The genus Grayia is native to the western United States ( Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington and Wyoming). It occurs in arid and semi-arid regions and grows on heavy to sandy loam to alkaline or salty soil barely. Although the distribution areas of each species overlap, but the species colonize different habitats respectively.

System

The first description of the genus Grayia was made in 1840 by William Jackson Hooker and George Arnott Walker Arnott ( in: The Botany of Captain Beechey 's Voyage, pp. 387-388 ). The genus name honors the American botanist Asa Gray. The genus in those days consisted of only one type, Grayia polygaloides Hook. & Arn. (nom. illeg. ), the spinosum on Chenopodium Hook. back and by Alfred Moquin - Tandon 1849 the valid name Grayia spinosa ( Hook. ) Moq. obtained.

Grayia belongs to the tribe of the subfamily Atripliceae Chenopodioideae in the family Amaranthaceae. By 2010, the species was considered monotypic. After phylogenetic studies affiliated Zacharias & Baldwin ( 2010) and the genus Zuckia Standlschmaus. here a.

Thus, the genus Grayia includes four types:

• Grayia arizonica ( Standl. ) EHZacharias (. Syn. Zuckia arizonica Standlschmaus, Zuckia brandegeei var arizonica ( Standl. ) SLWelsh ): This species occurs in Arizona and Utah and is referred to as " Arizona siltbush ".
• Grayia brandegeei A.Gray (syn. Zuckia brandegeei ( A. Gray ) SLWelsh & Stutz ): This species occurs in Colorado, Arizona and Utah and is " Brandegee 's siltbush " called.
• Grayia plummeri ( Stutz & SCSand. ) EHZacharias (syn. Grayia brandegeei var plummeri Stutz & SC sand, Zuckia var brandegeei plummeri ( Stutz & SCSand ) Dorn. . ): She comes in Colorado, Wyoming, New Mexico and Utah is known as " Plummer's siltbush " before and.
• . Grayia spinosa ( Hook. ) Moq: It is widespread in Colorado, Idaho, Montana, Oregon, Washington, Wyoming, Arizona, California, Nevada and Utah; its common name is " spiny hopsage ".

Swell

• Elizabeth H. Zacharias, Bruce G. Baldwin: A Molecular Phylogeny of North American Atripliceae ( Chenopodiaceae ), with Implications for Floral and Photosynthetic Pathway evolution. In: Systematic Botany, Volume 35 (4 ), 2010, pp. 839-857. doi: 10.1600/036364410X539907 (Sections Description, occurrence, systematics )