''Ceanothus pauciflorus'', known by the common name Mojave ceanothus, is a species of flowering

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 ...

in the

buckthorn ''Rhamnus'' is a genus of about 140 accepted species of shrubs or small trees, commonly known as buckthorns, in the family Rhamnaceae. Its species range from tall (rarely to ) and are native mainly in east Asia and North America, but found thr ...

family,

Rhamnaceae The Rhamnaceae are a large Family (biology), family of flowering plants, mostly trees, shrubs, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order Rosales. The family contains about 55 genera and 950 specie ...

. It is native to the

Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural list of regions of the United States, region of the United States that includes Arizona and New Mexico, along with adjacen ...

(

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 ...

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 ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, and

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 ...

) and

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, where it grows primarily in

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

communities at moderate to high elevations. It is characterized by oppositely arranged leaves, corky stipules and white flowers. It was formerly known as ''Ceanothus greggii''.

Description

''Ceanothus pauciflorus'' is a many-branched shrub with woody parts that are gray in color and somewhat woolly. The flowers bloom in spring.Blakely, Larry
Desert Ceanothus, Ceanothus greggii A. Gray var. vestitus (E. Greene) McMinn (Rhamnaceae)
, Who's in a Name? People Commemorated in Eastern Sierra Plant Names Blooms are considered highly fragrant. ''C. pauciflorus'' is eagerly browsed by

livestock Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...

and wild

ungulate Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...

s such as

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whit ...

and

desert bighorn sheep The desert bighorn sheep (''Ovis canadensis nelsoni'') is a subspecies of bighorn sheep (''Ovis canadensis'') that is native to the deserts of the United States' intermountain west and southwestern regions, as well as northwestern Mexico. The ...

Morphology

This species is a

, around 0.2 to 4 m tall. The

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

is ascending to erect, and generally branches from at or near the base. The

twig A twig is a thin, often short, branch of a tree or Bush (plant), bush. The buds on the twig are an important diagnostic characteristic, as are the abscission scars where the leaves have fallen away. The color, texture, and patterning of the t ...

s are colored a pale gray to more or less white, and are densely

puberulent Trichomes (; ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

to short-tomentose. The

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

leaves are arranged oppositely, on a petiole 1 to 3 mm long, and with a leaf blade 5 to 20 mm long by 3 to 19 mm wide. The adaxial surface of the leaf is concave, colored gray-green to yellow-green, and puberulent, becoming glabrous (smooth) in age. The abaxial surface of the leaf is convex, colored gray-green, and is glabrous or has short, curly hairs. The tip of the leaf is generally shaped acute to obtuse. The margins of the leaf may have teeth. The stipule is a knob-like structure. 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 ...

is a small (less than 2 cm long) cluster of many white

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s on short lateral branches. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is a horned capsule a few millimeters wide which bursts explosively to expel the three seeds inside, which require thermal

scarification Scarification involves scratching, etching, burning/ branding, or superficially cutting designs, pictures, or words into the skin as a permanent body modification or body art. The body modification can take roughly 6–12 months to heal. In t ...

from

wildfire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

before they can

germinate Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an flowering plant, angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the sp ...

Taxonomy

This species is a member of the ''Ceanothus''

subgenus In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

''Cerastes''.

Classification

This species was originally discovered to science by Spanish botanists

Martín Sessé y Lacasta Martín Sessé y Lacasta (December 11, 1751 – October 4, 1808) was a Spanish botanist, who relocated to New Spain (now Mexico) during the 18th century to study and classify the flora of the territory. Background Sessé studied medicine in ...

and

José Mariano Mociño José Mariano Mociño Suárez Lozano (24 September 1757 – 12 June 1820), or simply José Mariano Mociño, was a naturalist from Mexico. After having studied philosophy and medicine, he conducted early research on the botany, geology, and anthro ...

on an expedition to western Mexico in 1790 to 1791. It was later described as ''Ceanothus pauciflorus'' by

Augustin Pyramus de Candolle Augustin Pyramus (or Pyrame) de Candolle (, , ; 4 February 17789 September 1841) was a Swiss people, Swiss botany, botanist. René Louiche Desfontaines launched de Candolle's botanical career by recommending him at a herbarium. Within a couple ...

in 1825, based on the illustrations made by Sessé and Mociño expedition. Sessé and Mociño also collected a flowering specimen of ''Ceanothus'', later determined to be ''Ceanothus pauciflorus.'' Because ''Ceanothus pauciflorus'' was the first description of the plant, subsequent descriptions were reduced to synonyms. It was named by

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 ...

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

in 1853 as ''Ceanothus greggii'' in honor of its collector, Josiah Gregg, who found the plant in 1847 at the site of the

Battle of Buena Vista The Battle of Buena Vista (February 22–23, 1847), known as the Battle of La Angostura in Mexico, and sometimes as Battle of Buena Vista/La Angostura, was a battle of the Mexican–American War. It was fought between U.S. forces, largely vol ...

in the Mexican state of

Coahuila Coahuila, formally Coahuila de Zaragoza, officially the Free and Sovereign State of Coahuila de Zaragoza, is one of the 31 states of Mexico. The largest city and State Capital is the city of Saltillo; the second largest is Torreón and the thi ...

during the

Mexican–American War The Mexican–American War (Spanish language, Spanish: ''guerra de Estados Unidos-México, guerra mexicano-estadounidense''), also known in the United States as the Mexican War, and in Mexico as the United States intervention in Mexico, ...

Edward Lee Greene Edward Lee Greene (August 20, 1843–November 10, 1915) was an American botanist known for his numerous publications including the two-part ''Landmarks of Botanical History'' and the describing of over 4,400 species of plants in the American W ...

named it as ''Ceanothus vestitus'', but recent taxonomic analysis finds that ''C. vestitus'' does not have enough morphological evidence to warrant a separate taxon from ''C. pauciflorus''.

Distribution and habitat

''Ceanothus pauciflorus'' is widely distributed throughout the

southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural list of regions of the United States, region of the United States that includes Arizona and New Mexico, along with adjacen ...

and northern

. In the United States, it is found in the states of

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 ...

, and

. It is widely distributed in Mexico, found from

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

and

south to

Oaxaca Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 32 states that compose the political divisions of Mexico, Federative Entities of the Mexico, United Mexican States. It is divided into municipalities of Oaxaca, 570 munici ...

. In Baja California, it is found from the Sierra Juarez to the Sierra de la Asamblea. However, it is replaced in a portion of its range in California and Baja California with a close relative, '' Ceanothus perplexans''. This species is found on a variety of habitats over its wide distribution, although it is almost always found in shrub-dominated communities like

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

and matorral at moderate to high elevations (550 to 2600 m).

References

External links

Calflora Database: ''Ceanothus greggii'' (desert ceanothus)Jepson Manual treatment of ''Ceanothus greggii''USDA Plants Profile for ''Ceanothus greggii'' (desert ceanothus)UC Photos gallery — ''Ceanothus greggii''
{{Taxonbar, from=Q59420238 pauciflorus Flora of California Flora of Northeastern Mexico Flora of Northwestern Mexico Flora of the South-Central United States Flora of the Southwestern United States Flora of the California desert regions Flora of the Sierra Nevada (United States) North American desert flora Natural history of the California chaparral and woodlands Natural history of the Mojave Desert Natural history of the Peninsular Ranges Natural history of the Transverse Ranges Plants described in 1825 Taxa named by Augustin Pyramus de Candolle Flora without expected TNC conservation status