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iAcanthomintha duttonii
Acanthomintha duttonii. Photo credit: John Game
Conservation status
Endangered
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Lamiales Family: Lamiaceae Genus: Acanthomintha Species: A. duttonii
Binomial name
Acanthomintha duttonii (Abrams) Jokerst

Acanthomintha duttonii is an endangered species^[1] of the genus Acanthomintha that occurs in San Mateo County, California. The common name of this rare wildflower is San Mateo Thornmint. A. duttonii is known to occur on Serpentine soils near the Crystal Springs Reservoir in a six mile long strip on the east side of Montara Mountain at elevations of approximately 150 to 300 meters. In recent years the population has declined to a number of about 5000 individuals. This self pollinating plant can be considered critically endangered in a practical sense due to scarcity of numbers in a fragmented habitat and encroachment by urban development.^[2] It is named after Harry Arnold Dutton (1873-1957), who, in 1949, located a patch of Cupressus abramsiana on nearby Butano Ridge, whose location had been uncertain for fifty years.^[3] Image File history File links Blue_question_mark. ... The conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. ... Image File history File links Status_iucn3. ... The critically endangered Amur Tiger, a rare subspecies of tiger. ... For other uses, see Scientific classification (disambiguation). ... For other uses, see Plant (disambiguation). ... It has been suggested that Angiospermae, and Anthophyta be merged into this article or section. ... Magnoliopsida is the botanical name for a class: this name is formed by replacing the termination -aceae in the name Magnoliaceae by the termination -opsida (Art 16 of the ICBN). ... Families See text The Order Lamiales is a taxon in the asterid group of dicotyledonous flowering plants. ... Genera Many, see text Ref: Delta 2002-07-22 Lamiaceae, or the Mint family, is a family of plants in about 180 genera and some 3,500 species. ... In biology, binomial nomenclature is the formal method of naming species. ... The critically endangered Amur Tiger, a rare subspecies of tiger. ... In biology, a species is one of the basic units of biodiversity. ... Official website: http://www. ... Rare species is an organism which is very uncommon or scarce. ... Crystal Springs Reservoir is a reservoir located in the northern Santa Cruz Mountains of San Mateo County. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ... Look up habitat in Wiktionary, the free dictionary. ...

Morphology

Features in common with other thornmints

All thornmints are aromatic annual wildflowers with square erect stems and petioled leaves. Inflorescences of the Acanthomintha genus are described as "head-like, in terminal clusters" by the genus authority James D. Jokerst.^[4] In Acanthomintha, leaf veins are conspicuous and the leaf margins are often spiny. The characteristics of the flower of this entire genus are that of a two-lipped calyx and lobes spine-tipped,^[4] re-inforcing the basis of the common name. All Acanthomintha have the upper three lobes of its calyx acuminate and the lower two lobes oblong in shape; furthermore, all Acanthomintha corollae are funnel shaped and white. Each Acanthomintha species has four stamens, with the upper two reduced. Thornmint styles are slender and their fruit is ovoid in shape with a smooth exterior texture. In chemistry, an aromatic molecule is one in which electrons are free to cycle around circular arrangements of atoms, which are alternately singly and doubly bonded to one another. ... Five wildflower species Penstemon strictus A wildflower (or wild flower) is a flower that grows wild, meaning it was not intentionally seeded or planted. ... Leaf of Dog Rose (Rosa canina), showing the petiole and two leafy stipules In botany, the petiole is the small stalk attaching the leaf blade to the stem. ... The arrangements of veins and veinlets is called venation. ... The word calyx has several possible meanings: Look up calyx in Wiktionary, the free dictionary. ... In botany, the following terms are used to describe the shape of plant leaves: cordate leaf Acicular: slender and pointed Alternate (alternifolia): Arranged alternately Bipinnate (bipinnata): Each leaflet also pinnate Cordate (cordata): Heart-shaped, stem attaches to cleft Cuneate: Triangular, stem attaches to point Deltoid: Triangular, stem attaches to side... Corolla can be: A Latin-language term for crown The Toyota Corolla, a model of automobile manufactured by Toyota The corolla is one whorl of the perianth of a flower and composed of petals The town of Corolla, North Carolina This is a disambiguation page, a list of pages that... Stamens of the Amaryllis with prominent anthers carrying pollen Insects, while collecting pollen, accidentally transfer it from one flower to another, bringing about pollination The stamen is the male organ of a flower. ... Amaryllis style and stigmas A carpel is the female reproductive organ of a flower; the basic unit of the gynoecium. ... An oval or ovoid was originally an egg shape (from Latin OVVM); it is now usually used to refer to ellipses, but can also mean any similar shape, such as egg shapes or race-course shapes (a semicircle on either side of a quadrilateral). ...

Distinguishing features of the species A. duttonii

A. duttonii has a stem which is generally unbranched and less than twenty centimeters in length; the stem may present short hairs or none at all. Leaves of this species are eight to twelve millimeters in length, lanceolate to obovate in shape. The margins of this spiny leaf are occasionally serrate. The terminal inflorescences have bracts of about five to eleven millimeters; moreover, these bracts are ovate and green at the flower, with five or seven marginal spines, each three to seven millimeters. The virtually hairless to sparse short haired calyx is five to eight millimeters in length, while the corolla is 12 to 16 millimeters in extent. The white corolla is often tinged lavender in color; the corolla throat is cream colored and its upper lip is hooded, while the longer lower lip is reflexed and three-lobed. The upper lip is more diminutive than the lower, and is entire and shallowly hooded. A. duttonii upper stamens are fertile, and the anthers are short and hairy. The style is glabrous. Lanceolate refers to a narrow oval shape that is pointed at both ends. ... In botany, the following terms are used to describe the shape of plant leaves: cordate leaf Acicular: slender and pointed Alternate (alternifolia): Arranged alternately Bipinnate (bipinnata): Each leaflet also pinnate Cordate (cordata): Heart-shaped, stem attaches to cleft Cuneate: Triangular, stem attaches to point Deltoid: Triangular, stem attaches to side... The leaves of a Beech tree A leaf with laminar structure and pinnate venation In botany, a leaf is an above-ground plant organ specialized for photosynthesis. ... Flower of the Primrose Willowherb (Ludwigia octovalvis) showing petals and sepals A sepal is one member or part of the calyx of a flower. ... Corolla can be: A Latin-language term for crown The Toyota Corolla, a model of automobile manufactured by Toyota The corolla is one whorl of the perianth of a flower and composed of petals The town of Corolla, North Carolina This is a disambiguation page, a list of pages that... Stamens of the Amaryllis with prominent anthers carrying pollen Insects, while collecting pollen, accidentally transfer it from one flower to another, bringing about pollination The stamen is the male organ of a flower. ... Flower of the spider tree (Crateva religiosa) with its numerous conspicuous stamens The stamen is the male organ of a flower. ... In Botany, glabrous is used to describe something as smooth or having no hair or similar growth (see indumentum). ...

Distribution and habitat

This species is normally associated with serpentine grasslands or sloping chaparral of the San Francisco Peninsula. The range of is sharply limited within a portion of central San Mateo County on the eastern lower slopes of the Santa Cruz Mountains.^[5] Specific plant communities where this species is found are chaparral as well as foothill or valley grasslands. San Mateo Thornmint populations occupy slopes or flatland with deep, heavy clay soil inclusions. The single remaining large population, in Edgewood County Park, is a relict of a more extensive colony damaged by off road motor-vehicle use. There is an introduced population at Pulgas Ridge,^[6] and native fragments along the lower slopes above Crystal Springs Reservoir in a six mile long fragmented strip that includes the Edgewood colony. Serpentine Serpentine is a group of common rock-forming hydrous magnesium iron phyllosilicate ((Mg, Fe)3Si2O5(OH)4) minerals; it is also often rich in other metal ores, including chromium, manganese, cobalt and nickel. ... Chaparral is a shrubland biome found primarily in California, USA, that is shaped by a Mediterranean climate (mild, wet winters and hot dry summers) and wildfire. ... USGS Satellite photo of the San Francisco Bay Area. ... San Mateo County is a county located in the San Francisco Bay Area. ... The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central California. ... Chaparral is a shrubland biome found primarily in California, USA, that is shaped by a Mediterranean climate (mild, wet winters and hot dry summers) and wildfire. ... Fljótsdalur in East Iceland, a rather flat valley Mt. ... An Inner Mongolian Grassland. ... The term relict is used to refer to surviving remnants of natural phenomena. ... Crystal Springs Reservoir is a reservoir located in the northern Santa Cruz Mountains of San Mateo County. ...

This species is only known to grow on Serpentine soils. Serpentine soils normally provide an inhospitable environment for vegetation. Several parameters contribute to the difficulty of serpentine soils to support plant growth: a low calcium-magnesium ratio, lack of essential nutrients including nitrogen, potassium, and phosphorus, and high concentrations of heavy metals. General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... A nutrient is either element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Atomic mass 39. ... General Name, Symbol, Number phosphorus, P, 15 Chemical series nonmetals Group, Period, Block 15, 3, p Appearance waxy white/ red/ black/ colorless Atomic mass 30. ... Heavy metals, in chemistry, are chemical elements of a particular range of atomic weights. ...

Conservation

This species became state of California listed as endangered in July 1979 and federally listed as endangered on October 18, 1989. The state of California lists San Mateo Thornmint as "rare, threatened, or endangered in California" under List 1B.1, and further classifies this plant as "seriously endangered in California". A state of California endangerment rank of S1.1 has been assigned, implying that there are fewer than six occurrences, fewer than 1000 individuals or fewer than 2000 acres. In the case of A. duttonii, the criteria of occurrences and acreage may both be present. A global rank of G1 (Critically imperilled globally) has been attached to this wildflower. Significant threats to the limited population of A. duttonii exist due to continuing urbanization of the San Francisco Peninsula, an inherently fragmented population and off road vehicle use.^[7] Two and possibly three colonies of San Mateo Thornmint have been eradicated in the last two decades by off road vehicle use and road maintenance crews. October 18 is the 291st day of the year (292nd in leap years). ... 1989 (MCMLXXXIX) was a common year starting on Sunday of the Gregorian calendar. ... This article is about the U.S. state. ... USGS Satellite photo of the San Francisco Bay Area. ...

References

Genera Many, see text Ref: Delta 2002-07-22 Lamiaceae, or the Mint family, is a family of plants in about 180 genera and some 3,500 species. ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... November 23 is the 327th day of the year (328th in leap years) in the Gregorian Calendar, with 38 days remaining. ... The University of California (UC) is a public university system in the state of California. ... The USFWS logo The United States Fish and Wildlife Service is a unit of the United States Department of the Interior that is dedicated to managing and preserving wildlife. ...

External links

• Thornmint taxonomy
• U.S. Department of Agriculture species page