''Chloracantha'' is a monotypic genus of flowering plants in the aster family, containing the single species ''Chloracantha spinosa''. It is distributed in the southwestern and south-central United States ( CA NV AZ UT NM TX OK LA), most of Mexico, and much of Central America. Its English language common names include spiny chloracantha, spiny aster, devilweed aster, and Mexican devilweed.''Chloracantha spinosa''.
Integrated Taxonomic Information System (ITIS). In Spanish it is known as ''espina de agua'', ''espinaza'', and ''espinosilla''. This species is a perennial herb or

subshrub A subshrub (Latin ''suffrutex'') or dwarf shrub is a short shrub, and is a woody plant. Prostrate shrub is a related term. "Subshrub" is often used interchangeably with "bush".Jackson, Benjamin, Daydon; A Glossary of Botanic Terms with their Der ...

; its green stems look more herbaceous than woody, "but it behaves more like a subshrub",''Chloracantha''.
Flora of North America. with its tough stems living for several years and rapidly developing vascular cambia. The stems are hairless and sometimes waxy in texture, and some of the lateral branches may be sharply angled and reduced in size, becoming

thorns Thorn(s) or The Thorn(s) may refer to: Botany * Thorns, spines, and prickles, sharp structures on plants * ''Crataegus monogyna'', or common hawthorn, a plant species Comics and literature * Rose and Thorn, the two personalities of two DC Com ...

. The alternately arranged leaves persist for only a short time and then fall away. Large colonies of these bare stems proliferate from a robust

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

s. The stems usually reach a maximum height around 1.5 meters, but can well exceed 2 meters at times. They bear loose arrays of many

flower heads A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

each roughly half a centimeter long and wide. The head is lined with layers of hairless phyllaries. It contains up to 33 coiling white ray florets and many yellow disc florets. The fruit is a cypsela with a pappus of many barbed bristles. This plant is known from dry habitat and moist spots, such as streambanks and

seeps A petroleum seep is a place where natural liquid or gaseous hydrocarbons escape to the earth's atmosphere and surface, normally under low pressure or flow. Seeps generally occur above either terrestrial or offshore petroleum accumulation stru ...

. It tolerates some saline habitat types.''Chloracantha spinosa'' var. ''spinosa''.
The Jepson eFlora 2013. ;varieties # ''Chloracantha spinosa'' var. ''spinosa'' # ''Chloracantha spinosa'' var. ''jaliscensis'' (McVaugh) S.D. Sundb. -

Jalisco Jalisco (, , ; Nahuatl: Xalixco), officially the Free and Sovereign State of Jalisco ( es, Estado Libre y Soberano de Jalisco ; Nahuatl: Tlahtohcayotl Xalixco), is one of the 31 states which, along with Mexico City, comprise the 32 Federal En ...

, Nayarit # ''Chloracantha spinosa'' var. ''spinosissima'' (Brandegee) S.D.Sundb. - Baja California # ''Chloracantha spinosa'' var. ''strictospinosa'' S.D.Sundb. -

Chiapas Chiapas (; Tzotzil language, Tzotzil and Tzeltal language, Tzeltal: ''Chyapas'' ), officially the Free and Sovereign State of Chiapas ( es, Estado Libre y Soberano de Chiapas), is one of the states that make up the Political divisions of Mexico, ...

Michoacán Michoacán, formally Michoacán de Ocampo (; Purépecha: ), officially the Free and Sovereign State of Michoacán de Ocampo ( es, Estado Libre y Soberano de Michoacán de Ocampo), is one of the 32 states which comprise the Federal Entities of ...

Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...

El Salvador El Salvador (; , meaning " The Saviour"), officially the Republic of El Salvador ( es, República de El Salvador), is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south b ...

Guatemala Guatemala ( ; ), officially the Republic of Guatemala ( es, República de Guatemala, links=no), is a country in Central America. It is bordered to the north and west by Mexico; to the northeast by Belize and the Caribbean; to the east by H ...

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. The republic of Honduras is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Oce ...

, Nicaragua, Panama

References

External links

''Chloracantha spinosa''.
USDA PLANTS.
''Chloracantha spinosa''.
CalPhotos. Monotypic Asteraceae genera Flora of Mexico Flora of the United States Flora of Central America Astereae {{Astereae-stub