Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts
The botanical glossary used in Southwest Desert Flora is an alphabetical list of words or terms relevant to the descriptions here. In addition to the more difficult or unusual words defined here the glossary also provides definitions to some of the more common day-to-day botanical words that are not necessarily understood by all readers. This glossary is regularly updated or modified.
Regular; radially symmetrical; may be bisected into similar halves in at least two planes. Applies e.g. to steles and flowers in which the perianth segments within each whorl are alike in size and shape; compare Regular; contrast with Asymmetrical, Irregular, Zygomorphic.
A fan or cone-shaped deposit of granular fertile soil deposited by streams or other drainage from mountainous terrain. The formation of one or more alluvial fans into a single fan against a slope is called a bajada (see Bajada).
Leaves or flowers borne singly at different levels along a stem includes spiralled parts; or (as preposition) when something occurs between something else, for example stamens alternating with petals; compare Opposite
1. (of a flower) the period during which pollen is presented and/or the stigma is receptive.
2. (of a flowering plant) the period during which flowers in anthesis are present. note: not defined for some cases, such as when pollen is released in the bud.
An alluvial fan of deposits of sediment by a stream settling onto flats at the front of a mountain. Derived from the Spanish word bajada; meaning with a sense of “descent” or “inclination” (see Alluvial fan).
John Milton Bigelow, (1804-1878), American physician and botanist; Dr. Bigelovii was a professor of botany who collected in the western United States under Joseph Whipple Congdon in the Pacific Railroad Survey of 1853-1854. In addition, he worked with 3 top American botanists of the day, John Torrey, Asa Gray, and George Engelmann; and had a significant collection of California plants that yielded many new species.
Falling off early, for example the sepals of poppies, that fall off when the petals begin to open; compare Persistent and Fugacious.
A tufted form or growth; e.g. the growth form of some grasses, growing in tufts.
A soil type rich in calcium carbonate (CaCO3). Southwestern calcareous soils contain heavy amounts of limestone and lime. (see Caliche and Limestone.
A hardened natural cement of calcium carbonate (CaCO3) that binds other materials—such as gravel, sand, clay, and silt. It is generally light-colored and occurs in arid or semi-arid regions in the Sonoran and Mojave Deserts. The term caliche is Spanish originally from the Latin calx, meaning lime. see Calcareous and Limestone.
(adj. calyculate) (calyculi)
(1) a cup-shaped structure formed from bracts;
(2) in some Asteraceae, an extra set of bracts or phyllaries just below the involucre simulating a calyx; an involucel.
(Plural calyces) the outer whorl of a flower, usually green; the sepals of one flower collectively.
A tube formed by the fusion of the sepals (calyx), at least at the base.
Approaching white in color, covered with dense white (or grayish-white tricomes) down or wool.
A dense cluster of sessile, or almost sessile, flowers or florets; a head.
A dry fruit formed from two of more united carpels and dehiscing when ripe (usually by splitting into pieces or opening at summit by teeth or pores).
Count Alexandre Henri Gabriel de Cassini, (1781–1832), was a French botanist and naturalist, who specialized in Asteraceae, the sunflower family which was known as family Compositae at the time.
A spike, usually pendulous, in which the mostly small flowers are unisexual and without a conspicuous perianth; e.g. willows, poplars, oaks and casuarinas. The individual flowers often have scaly bracts; they are generally wind-pollinated. The catkins are usually shed as a unit.
Caudex (plural: caudices)
Literally the stem of a plant, but also used to mean a rootstock, or particularly a basal stem structure or storage organ from which new growth arises. See also Connate
Literally meaning "stem-like" or "caudex-like", is sometimes used to mean "pachycaul", meaning "thick-stemmed". See also Caudex
Dr. James Graham Cooper, (1830-1902), geologist of the Geological Survey of California, who collected plants in the Mojave Desert in 1861. He was the son of William Cooper, one of the founders of the New York City Museum of Natural History.
Fleshy, swollen stem base, usually underground, storing food reserves, with buds naked or covered by very thin scales; a type of rootstock. Adjectives derived from "corm" include "cormose" and "cormous";.
(adjective: coronate) literally, crown
1. in flowering plants, ring of structures that may be united in a tube, arising from the corolla or perianth of a flower and standing between the perianth lobes and the stamens. The trumpet of a daffodil is a corona.
2. in grasses, a hardened ring of tissue surmounting the lemma in some species.
Corymb (Adjective corymbose) an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top superficially resembling an umbel, and may have a branching structure similar to a panicle. Flowers in a corymb structure can either be parallel, or alternate, and form in either a convex, or flat form.
John Thomas Coulter, (1793-1843) Irish botanist, physician and explorer. Dr. Coulter studied botany in Switzerland under Augustin de Candolle, discovered the Colorado Desert and was first to collect the Matilija Poppy among other plants. John Thomas Coulter was the first botanist to collect in Arizona. Not to be confused with John Merle Coulter, (1851-1928), also a botanist who was recognized with Erigeron coulteri.
Leaf or fruit with blunt, rounded teeth or scalloped margin.
The term cultivar is derived from cultivated variety and denotes an assemblage of cultivated plants clearly distinguished by one or more characters (morphological, physiological, cytological, chemical or other); when reproduced (sexually or asexually), the assemblage retains its distinguishing characters. A cultivar may arise in cultivation or be introduced from the wild. It is a variant of horticultural interest or value. Cultivar names are written with single quotation marks around them e.g. 'Blue Carpet', 'Alba'. All new names established after 1 January 1959, must be in common language (that is, not in Latin) but names established in Latin prior to this date are retained in Latin form.
Forking into two equal branches. This may result from an equal division of the growing tip, or may be sympodial, in which the growing tip is aborted and replaced. Typically refers to mode of branch growth, as in Aloe dichotoma, but also to other organs, such as the thorns of various species of Carissa (which morphologically are branches) and thalli or hyphae of various algae and fungi.
Resembling a disc or plate, having both thickness and parallel faces and with a rounded margin. Also used to describe the flower head of Compositae where there are no ray florets, but only disc florets.
Occurring in widely separated geographic areas, distinctly separate; applies to a discontinuous range in which one or more populations are separated from other potentially interbreeding populations far enough as to preclude gene flow between them.
William Hemsley Emory, (1811-1887), was born in Maryland of prominent parents and was an Army officer. Boundary surveys were a big part of his life as he was the Director of the Mexican Boundary Survey. Mr. Emory also conducted surveys along the Texas-Mexican border in 1844 and became part of the Northeastern boundary survey between the United States and Canada. Between 1848 and 1853 he conducted a boundary survey along the United States-Mexican border, and surveyed the Gadsden Purchase from 1854 to 1857.
George Engelmann, (1809-1884), a German-born St. Louis physician and botanist, and prolific author on cacti, North American conifers and oaks. He was educated at the gymnasium in Frankfurt and then at the University of Heidelberg, the University of Berlin and the University of Wurzburg where he received his M.D. degree.
Local extinction, or extirpation, is the condition of a species (or other taxon) that ceases to exist in the chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions.
Vascular plant without significant woody tissue above or at the ground. Forbs and herbs may be annual, biennial, or perennial but always lack significant thickening by secondary woody growth and have perennating buds borne at or below the ground surface.
John Charles Fremont (1813-1890), known as the Pathfinder, Army officer and presidential candidate who collected plants on four hazardous journeys exploring the western United States. Best known for cartography and exploring, he was intensely interested in all natural sciences.
Glaucous (Botanical adjective), leaves or other herbage that is pale bluish-grey, bluish-green or whitish which describes the pale grey or bluish-green appearance of the surfaces of some plants and that is often easily rubbed off. Often applied to plants with a woolly or arachnoid surface, but properly referring to powdery or waxy surfaces, meaning those with a waxy bloom.
James Duncan Graham, (1799-1865), a West Point Graduate and U.S. Army Officer. Mr. Graham is the namesake of Mount Graham, in Graham County, Arizona, and Graham County, Arizona was named after Mount Graham. Mr. Graham is also one of the founders of the United States army's topographical section and well known for his map making skills.
Asa Gray, (1810-1888), one of the most eminent American botanists and professor at Harvard, who played an important part in the identification of many Sierra wildflowers, and whose guides in Yosemite were John Muir and Galen Clark.
The Great Basin Desert is defined by its animals and plants, yet the exact boundaries are unclear. It is a temperate desert with hot, dry summers and snowy winters. The desert spans a large part of the state of Nevada, and extends into western Utah, eastern California, and Idaho. The desert is one of the four biologically defined deserts in North America, in addition to the Mojave, Sonoran, and Chihuahuan Deserts.
Josiah Gregg, (1806-1850) was an American merchant, explorer and naturalist. He was also wrote about the American Southwest and Northern Mexico regions. Mr. Gregg collected many previously undescribed plants on his merchant trips and during the Mexican–American War after which he went to California.
A seed-bearing plant with unenclosed ovules borne on the surface of a sporophyll; includes, among others, conifers, Ginkgo, Gnetum and cycads. From gymno = naked, exposed; compare angio = covered, enclosed.
Honeybees are not native to North America and compete with Native Bees. Honeybees were introduced to North America by early settlers and compete with Native Bees. Honeybees are most important to non-native agricultural crops - see Native bees.
Native to the area; its presence in that region is the result of only natural processes with no human intervention; not introduced and not necessarily confined to the region discussed (hardly distinct from ‘native’ but usually applied to a smaller area). The term is equivalent to "native" in less scientific usage. For example, the Joshua Tree (Yucca brevifolia) is native to parts of the southwest but indigenous to Joshua National Park, California. Compare; Endemic; Native.
Invasive species; U.S.D.A., Executive Order 13112; an invasive species is defined as a species that is: 1) non-native (or alien) to the ecosystem under consideration and 2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health.
A structure surrounding or supporting, usually a head of flowers. In Asteraceae, it is the group of phyllaries (bracts) surrounding the inflorescence before opening, then supporting the cup-like receptacle on which the head of flowers sits. In Euphorbiaceae it is the cuplike structure that holds the nectar glands, nectar, and head of flowers, and sits above the bract-like cyathophyll structure.
Keystone species (A species with a disproportionately large effect on its natural environment relative to its abundance. A keystone species is a plant or animal that plays a unique and crucial role in the way an ecosystem functions.
A specimen chosen by a later researcher to serve as if it were the holotype (specimen designated in the original description). It is chosen from among the specimens available to the original publishing author (the isotypes, syntypes and/or paratypes) of a scientific name when the holotype was either lost or destroyed, or when no holotype was designated. Also see Holotype.
1. a fruit characteristic of the family Fabaceae, formed from one carpel and either dehiscent along both sides, or indehiscent.
2. a crop species in the family Fabaceae.
3. a plant belonging to the Fabaceae family).
1. Small membranous appendage on the top of the sheath of grass leaves.
2. A minute adaxial appendage near the base of a leaf, e.g. in Selaginella.
3. Extended, strap-like corolla of some daisy florets. See Ligulate.
A sedimentary rock (CaCO3), composed mostly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3). see Calcareous Calcareous and Caliche Caliche.
Lindley, John, (1799-1865), the son of a nurseryman, assisted in his father's garden as a boy while collecting wildflowers in nearby areas. John Lindley has a remarkable life and he was one of the most industrious British botanists, author, gardener, orchidologist, and the first professor of botany at London University.
Very narrow in relation to its length, with the sides mostly parallel.
Carl Linnaeus, (1707-1778), a Swedish botanist, zoologist and physician known as the “father of modern taxonomy” which is the modern system of classifying all organisms. Dr. Linnaeus has inspired and influenced many generations of biologists.
Loam soil (loam soil is the only soil that is not predominantly sand, silt, or clay; they generally contain more nutrients, moisture, and humus than sandy soils; they have better drainage and infiltration of water and air than silt and clay-rich soils, and are easier to till than clay soils. The different types of loam soils each have slightly different characteristics, with some draining liquids more efficiently than others. Loam soil is suitable for growing most plant varieties.
Harold Frederick Loomis (1896-1976) was born in Farmington, New York and was a botanist and horticulturist by profession. He was also an authority on the millipedes of the West Indies and Central America. Mr. Loomis joined the U.S. Department of Agriculture in 1914 and studied diseases of crop plants.
The Madrean pine–oak woodlands are an ecoregion of the Tropical and subtropical coniferous forests biome, located in North America. They are subtropical woodlands found in the mountains of Mexico and the southwestern United States.
Marcescent refers to the retention of dead and dry elements that normally are shed on a living plant. A marcescent plant is therefore a plant that keeps some organs, most often leaves or flowers, after they die.
One segment of a fruit (a schizocarp) that splits at maturity into units derived from the individual carpels, or a carpel, usually 1-seeded, released by the break-up at maturity of a fruit formed from 2 or more joined carpels. (see Schizocarp).
North American Natives Bees occur naturally and evolved with and are important to native flowering plants. In North America, Native Bees are found wherever flowers bloom. Honeybees are not native to North America and compete with Native bees - see Honeybees.
Leaves or flowers borne at the same level but on opposite sides of the axis; or (as verb) when something occurs on the same radius as something else, for example anthers opposite sepals; compare Alternate.
1. leaf with veins radiating out from a central point (usually at the top of a petiole), resembling spread out fingers pointing away from the palm.
2. A compound palmate leaf has leaflets that radiate from a central point (usually at the top of a petiole).
pl. pappi In daisy florets, a tuft or ring of feather-like hairs, scales or bristles, borne above the ovary and outside the corolla and attached to the seeds, (representing the missing sepals/calyx); a tuft of hairs on a fruit; pappi aid in dispersal by wind. the puff-ball on a dandelion are the pappi.
Charles C. Parry, (1823-1890), an English-born American botanist and botanical collector with the Pacific Railway Survey who visited the Southwestern mountains and deserts many times and is remembered in the names of more than a score of southwestern native plants. Dr. Parry studied botany under John Torrey, Asa Gray and George Engelmann.
A pedicel is a stem that attaches single flowers to the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower. The stem or branch from the main stem of the inflorescence that holds a group of pedicels is called a peduncle.
1. a legume, the fruit of a leguminous plant, a dry fruit of a single carpel, splitting along two sutures.
2. siliqua and silicula, the fruit of Brassicaceae, a dry fruit composed of two carpels separated by a partition.
(adjective: prickly) hard, pointed outgrowth from the surface of a plant (involving several layers of cells but not containing a vein); sharp outgrowth from the bark, detachable without tearing wood; cf. thorn.
(plural rachises; rachides) the axis of an inflorescence or a pinnate leaf; for example ferns; secondary rachis is the axis of a pinna in a bipinnate leaf distal to and including the lowermost pedicel attachment.
Constantine Samuel Rafinesque-Schmaltz, (1783–1840), was a 19th-century person of wide-ranging knowledge and learning. He was self-educated in France and traveled to the United States, settling in Ohio in 1815, where he made notable contributions to botany and zoology. By 1818, he had collected and named more than 250 new species of plants and animals. Rafinesque published 6,700 binomial names of plants, many of which have priority over more familiar names. Some of the animals named by Rafinesque include the Mule Deer, Odocoileus hemionus, the Black-tailed Prairie Dog, Cynomys ludovicianus and the White-footed Mouse, Peromyscus leucopus. Although he was self taught and excelled in various fields of knowledge as a zoologist, botanist and writer, Rafinesque was thought to be eccentric and an erratic genius by many of his peers. In fact, during his lifetime, he was an outcast in the American scientific community. However, according to historian George Daniels, despite all his faults, “he made enormous contributions to the natural history phase of American science with the establishment of 34 genera and 24 species of American fishes.” He was also a brilliant teacher at Transylvania University. In 1841, Thomas Nuttall named a new genus Rafinesquia after him as he felt indebted to the naturalist, who had inspired his work and given Nuttall's Flora a positive review. The genus now contains two species, Rafinesquia californica California and Rafinesquia neomexicana.
(adj. Creeping rootstock; creeping stems;) A plant whose above ground stem originates from a rhizome. The stems grows horizontally under or along the ground and often sends out roots and shoots. New plants develop from the shoots.
A plant that colonises or occupies disturbed waste ground. Ruderal species typically dominate the disturbed area for a few years, gradually losing the competition to other native species. The word ruderal comes from the Latin rudus, meaning rubble.
Leaf description, shaped like the head of an arrow; narrow and pointed but gradually enlarged at base into two straight lobes directed downwards; may refer only to the base of a leaf with such lobe; compare Hastate.
(Botany - of a cymose inflorescence) Resembling a scorpion's tail, as in a scorpioid cyme; of a cymose inflorescence, when it branches alternately on one side and then the other; compare Helicoid; Circinate.
Arthur Carl Victor Schott, (1814-1875), was German-American naturalist, artist, topographical engineer, cartographer, botanist and geologist. In 1851, Schott worked as a member of William H. Emory's team in mapping the border separating Texas and the adjacent Mexican territory (Mexican Boundary Survey). Schott contributed more field data to the border maps than any other member of the team, and became one of the first surveyors of the Rio Grande.
Perennial, multi-stemmed woody plant that is usually less than 4 to 5 meters (13 to 16 feet) in height. Shrubs typically have several stems arising from or near the ground, but may be taller than 5 meters or single-stemmed under certain environmental conditions. Applies to vascular plants only.
A fruit (seed capsule) of 2 fused carpels with the length less than three times the width. When the length is greater than three times the width of the dried fruit it is referred to as a silique; compare Silique.
A fruit (seed capsule) of 2 fused carpels with the length being more than three times the width. When the length is less than three times the width of the dried fruit it is referred to as a silicle; compare Silicle.
Part of a flower or perianth segment, either sepal or petal; usually used when the parts of the perianth are difficult to distinguish, e.g. the petals (caylx) and sepals (corolla) share the same color, or the petals are absent and the sepals are colorful.
George G. Thurber, (1821-1890), was called the most accomplished horticulturist in America and botanist and quartermaster of the United States and Mexican Boundary Survey, 1850-1854. He was also an American pharmacist, self-taught botanist and avid plant collector.
John Torrey, (1796-1873), a professor of chemistry and one of the giants of North American botany who described hundreds of plants brought or sent back by such explorers as John C. Frement, William Emory, Charles Wilkes, Joseph Nicollet, Howard Stansbury and Charles Pickering.
Perennial, woody plant with a single stem (trunk), normally greater than 4 to 5 meters (13 to 16 feet) in height; under certain environmental conditions, some tree species may develop a multi-stemmed or short growth form (less than 4 meters or 13 feet in height). Applies to vascular plants only.
In non-filamentous plants, any hair-like outgrowth from epidermis, e.g. a hair or bristle; sometimes restricted to unbranched epidermal outgrowths.
(adjective umbellate) A racemose inflorescence in which all the individual flower stalks arise in a cluster at the top of the peduncle and are of about equal length; in a simple umbel, each stalk is unbranched and bears only one flower; a cymose umbel is an apparent umbel but its flowers open centrifugally.
Charles Wright, (1811-1885), an American botanical collector that collected plants and sending specimens to Professor Asa Gray at Harvard, eventually becoming one of his most trusted collectors. In 1851, with Gray’s help, Mr. Wright became part of the Mexican Boundary Survey, and helped collect many of the 2,600 species that were sent back to Professor John Torrey for description and identification. His name was honored by George Engelman who gave it to a cactus, Opuntia wrightii.
Xeromorph (A plant with structural features (e.g. hard or succulent leaves) or functional adaptations that prevent water loss by evaporation; usually associated with arid habitats, but not necessarily drought-tolerant; Also see Xerophyte.