''Echinocereus viridiflorus'' is a species of

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Gree ...

known by the common names nylon hedgehog cactus, green pitaya, and small-flowered hedgehog cactus. It is native to the central and south-central

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

and northern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, where it can be found in varied habitat types, including desert scrub,

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (se ...

s, dry

grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...

s, and short-grass prairie.''Echinocereus viridiflorus''.
Flora of North America. This cactus has a small spherical or cylindrical stem 3 centimeters to over 30 centimeters tall and up to 9 centimeters wide. It is mostly unbranched but it may occur in squat clusters of several branches. The body of the plant is ridged and lined with many

areole In botany, areoles are small light- to dark-colored bumps on cacti out of which grow clusters of spines. Areoles are important diagnostic features of cacti, and identify them as a family distinct from other succulent plants. Gordon Rowley - W ...

s bearing spines. The spines may be red, yellow, white, purplish, or bicolored, sometimes with darker tips. The flower is up to 3 centimeters long and has

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s in shades of yellowish, brownish, greenish, or occasionally red, with darker reddish midstripes. The tepals are thin at the tips.

Taxonomy

The

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

of the species is uncertain, with authors recognizing several varieties which are sometimes treated as separate species. One variety, var. ''davisii'' (sometimes called '' Echinocereus davisii''), Davis' green pitaya, is federally listed as an endangered species. This taxon is very small, reaching no more than 3 centimeters tall. It becomes smaller when water is scarce, withdrawing under the ground, sometimes leaving just some spines sticking out.''Echinocereus davisii''.
Flora of North Americavar. ''davisii''.
Center for Plant Conservation. It has yellow-green flowers. This rare variety is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

Brewster County, Texas Brewster County is a county located in the U.S. state of Texas. It is in West Texas and its county seat (and only city) is Alpine. It is one of the nine counties that comprise the Trans-Pecos region, and borders Mexico. Brewster County i ...

, where it grows in beds of ''

Selaginella ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...

'' in rocky soils of

novaculite Novaculite, also called Arkansas Stone, is a microcrystalline to cryptocrystalline rock type that consists of silica in the form of chert or flint. It is commonly white to grey or black in color, with a specific gravity that ranges from 2.2 to 2.5 ...

origin.USFWS
var. ''davisii'' Recovery Plan.
September 1984. There was only one population known as of 1984, and it probably will not expand its range because it is limited to a specific mineral substrate.

Subspecies

* ''Echinocereus viridiflorus'' subsp. ''correllii'' * ''Echinocereus viridiflorus'' subsp. ''viridiflorus'' Echinocereus virdiflorus

References

External links

USDA Plants Profile — ''Echinocereus viridiflorus''''Echinocereus viridiflorus'' Photo gallery
viridiflorus Cacti of Mexico Cacti of the United States Flora of the Great Plains (North America) Flora of the Chihuahuan Desert Flora of the Rio Grande valleys Flora of Colorado Flora of New Mexico Flora of Texas Flora of Wyoming {{cactus-stub