''Grayia'' is a genus of plants in the subfamily

Chenopodioideae The Chenopodioideae are a subfamily of the flowering plant family Amaranthaceae in the APG III system, which is largely based on molecular phylogeny, but were included – together with other subfamilies – in the family Chenopodiaceae, or goose ...

of the family

Amaranthaceae Amaranthaceae ( ) is a family of flowering plants commonly known as the amaranth family, in reference to its type genus '' Amaranthus''. It includes the former goosefoot family Chenopodiaceae and contains about 165 genera and 2,040 species, maki ...

. Common names are siltbush and hopsage. The four shrubby species occur in arid and semiarid regions of western

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Description

The species of ''Grayia'' are

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s or

subshrub A subshrub (Latin ''suffrutex'') or undershrub is either a small shrub (e.g. prostrate shrubs) or a perennial that is largely herbaceous but slightly woody at the base (e.g. garden pink and florist's chrysanthemum). The term is often interch ...

s reaching 15–150 cm. The stems grow erect or ascending and are much branched and woody. Young stems are densely hairy, later glabrescent, lateral branches sometimes becoming spiny. Young branches are ribbed or striate. The old bark is gray brown. There are prominent subglobose buds in the leaf axils. The alternate

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

of 6–80 × 1.5–42 mm are succulent or coriaceous. They are nearly sessile or basally tapering to short petioles. The green to grayish leaf blades can be elliptic, ovate, obovate, spatulate, or linear-oblanceolate, with entire margins and prominent midveins. Especially at the tips, the leaves are hairy with simple or branched hairs. The leaves have a "normal" (non-Kranz) anatomy. The plants are

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and contras ...

. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s consist of glomeruled male flowers arranged in interrupted axillary or terminal spikes or panicles, and of female flowers in terminal and axillary interrupted panicles. Male flowers are without

bracteole In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also look ...

s, comprising 4-5 membranous

perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower. It is a structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepal ...

lobes 1–1.8 mm long, connate to the middle, with hooded tips, and 4-5

stamens The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

opposite to perianth lobes, inserted on a disc, with non-exserting

anther The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s. The female flowers are sitting within 2 opposite

s, a perianth is lacking, they consist just of an ovary with 2 filiform, exserted stigmas. In fruit, the bracteoles enclosing the fruit become accrescent, folded along the midribs and connate nearly to the apex, 4–14 × 3–15 mm. Their shape can be orbicular, broadly elliptic, or cordate, their margins are usually entire, but sometimes wavy or extended into two wings, their surface is flat or ribbed, glabrous or hairy. Initially, bracteoles are yellowish-greenish or cream-colored, later they become reddish or pinkish. The orbicular, obovoid or laterally compressed-lenticular fruit (utricle) does not fall at maturity. The membranous

pericarp Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Fruitlike structures may develop directly from the seed itself rather th ...

is free or slightly adheres to the seed. The vertically or horizontally orientated seed has a brown to yellowish-brown, thin membranous seed coat. The annular embryo surrounds the copious farinaceous

perisperm In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the fema ...

. The flowering time is March to June. The

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

numbers are 2n = 18 (for the diploid '' Grayia arizonica'' and '' Grayia brandegeei'') and 2n = 36 (for the tetraploid ''

Grayia spinosa ''Grayia spinosa'' is a species of the genus ''Grayia (plant), Grayia'' in the subfamily Chenopodioideae of the flowering plant family Amaranthaceae, which is known by the common names hop sage and spiny hop sage. It is widely distributed across ...

'' and '' Grayia plummeri'').

Distribution

The genus ''Grayia'' is native in the western United States (

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

, and

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

). Some species are of limited range. The genus grows in

arid Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.Perez-Aguilar, L. Y., Plata ...

semiarid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of sem ...

regions on heavy clay, sandy loams, on alkaline or scarcely alkaline soils. Although overlapping in ranges, the species differ in the preferred soils.

Systematics

The genus ''Grayia'' has been first described by

William Jackson Hooker Sir William Jackson Hooker (6 July 178512 August 1865) was an English botany, botanist and botanical illustrator, who became the first director of Kew Gardens, Kew when in 1841 it was recommended to be placed under state ownership as a botan ...

and

George Arnott Walker-Arnott George Arnott Walker Arnott of Arlary (6 February 1799 – 17 April 1868) was a Scottish botanist. He collaborated with botanists from around the world and served as a Regius Professor of Botany (Glasgow), regius professor of botany at the Uni ...

in 1840 in: ''The Botany of Captain Beechey's Voyage'' (p. 387–388). It included just one species, ''Grayia polygaloides'' Hook. & Arn. (nom. illeg.) = ''Chenopodium spinosum'' Hook. = ''

'' (Hook.) Moq. The genus name was given in honour to the American botanist

Asa Gray Asa Gray (November 18, 1810 – January 30, 1888) is considered the most important American botany, botanist of the 19th century. His ''Darwiniana'' (1876) was considered an important explanation of how religion and science were not necessaril ...

. ''Grayia'' belongs to the tribe Atripliceae of the subfamily

in the

. Until 2010, the genus was treated as

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

. After

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

research, Zacharias & Baldwin (2010) included here the genus ''Zuckia''. Now ''Grayia'' comprises 4 species: * '' Grayia arizonica'' (Standl.) E.H.Zacharias, (Syn. ''Zuckia arizonica'' Standl., ''Zuckia brandegeei'' var. ''arizonica'' (Standl.) S. L. Welsh) - Arizona siltbush: in Arizona and Utah * '' Grayia brandegeei'' A. Gray (Syn. ''Zuckia brandegeei'' (A. Gray) S. L. Welsh & Stutz) - Brandegee's siltbush: in Colorado, Arizona, Utah * '' Grayia plummeri'' (Stutz & S.C.Sand.) E.H.Zacharias, (Syn. ''Grayia brandegeei'' var. ''plummeri'' Stutz & S. C. Sand., ''Zuckia brandegeei'' var. ''plummeri'' (Stutz & S. C. Sand.) Dorn) - Plummer's siltbush: in Colorado, Wyoming, New Mexico and Utah * ''

'' (Hook.) Moq., spiny hopsage: in Colorado, Idaho, Montana, Oregon, Washington, Wyoming, Arizona, California, Nevada and Utah.

References

Noel H. Holmgren
''Grayia''
in Flora of North America ''Grayia''
''Germplasm Resources Information Network'' - (GRIN) Online Database, accessdate 2013-07-10. ''Grayia'' first description, scanned at BHL
/ref> Elizabeth H. Zacharias, Bruce G. Baldwin (2010): ''A Molecular Phylogeny of North American Atripliceae (Chenopodiaceae), with Implications for Floral and Photosynthetic Pathway Evolution''. In: ''Systematic Botany'' 35(4), p.839-857.

External links

*
''Grayia''
at Tropicos * Stanley L. Welsh (2003)
''Zuckia''
in Flora of North America {{Taxonbar, from=Q5598313 Chenopodioideae Amaranthaceae genera Taxa named by George Arnott Walker Arnott Taxa named by William Jackson Hooker