''Phacelia'' (phacelia, scorpionweed, heliotrope) is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of about 200

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of annual or

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

plants Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars f ...

in the borage family, native to

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

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 ...

is particularly rich in species with over 90 recorded in the region. The genus is traditionally placed at

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

rank with the waterleafs ( Hydrophyllaceae) in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Boraginales. The

Angiosperm Phylogeny Group The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disc ...

, recognizing that the traditional Boraginaceae and Hydrophyllaceae are

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

with respect to each other, merges the latter into the former and considers the family basal in the Euasterids I

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

. Other botanists continue to recognize the Hydrophyllaceae and Boraginales after analysing the secondary structure of the ITS1 genetic region rather than its sequence for these higher taxonomic levels. This placed ''Phacelia'' within the Hydrophyllaceae. Further molecular taxonomic analysis of the Boraginales has divided the Boraginales in two and placed ''Phacelia'' among the monophyletic herbaceous Hydrophyllaceae in Boraginales II. The genus includes both annual and perennial species. Many have been cultivated as

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

and

honey plant Honeybees often collect nectar, pollen, or both from the following species of plants, which are called honey plants, for making honey. This is not an exhaustive list of the flowering plant species Honeybees will visit. Acanthace ...

s. There are reports that glandular hairs of stems, flowers and leaves of some species of ''Phacelia'' secrete oil droplets that can cause an unpleasant skin rash (

contact dermatitis Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes ...

) in some people, specifically from ''P. brachyloba'', ''P. campanularia'', ''P. crenulata'',Berry, C. Z., et al. (1962)
Dermatitis venenata from ''Phacelia crenulata''.
''Archives of Dermatology'' 85(6), 737-39. ''P. gina-glenneae'', ''P. grandiflora'', ''P. ixodes'', ''P. minor'', and ''P. pedicellata''. The major contact allergen of ''P. crenulata'' has been identified as geranyl

hydroquinone Hydroquinone, also known as benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene, having the chemical formula C6H4(OH)2. It has two hydroxyl groups bonded to a benzene ring in a ''para' ...

and of ''P. minor'' as geranylgeranylhydroquinone. The mining bee '' Andrena phaceliae'' is a specialist

pollinator A pollinator is an animal that moves pollen from the male anther of a flower to the female carpel, stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are ...

of this genus in the Eastern United States.

Selected species

File:Phacelia argentea 3.jpg, '' Phacelia argentea'' File:Phacelia bicolor trumpets.jpg, '' Phacelia bicolor'' File:Phaceliacalifornica.jpg, '' Phacelia californica'' File:Phacelia parryi form.jpg, '' Phacelia campanularia'' File:Phacelia congesta.jpg, '' Phacelia congesta'' File:Phacelia distans 7904.JPG, '' Phacelia distans'' File:Phacelia fremontii 7883.JPG, '' Phacelia fremontii'' File:Phacelia hastata large plant.jpg, '' Phacelia hastata'' File:Phacelia rotundifolia 3.jpg, '' Phacelia rotundifolia'' File:Phacelia secunda.jpg, ''

Phacelia secunda ''Phacelia'' (phacelia, scorpionweed, Heliotropium, heliotrope) is a genus of about 200 species of annual plant, annual or perennial plant, perennial herbaceous plant, herbaceous flowering plant, plants in the borage family, native to North Ameri ...

'' File:Phacelia sericea 5277.JPG, '' Phacelia sericea'' File:Phacelia tanacetifolia 7738.JPG, '' Phacelia tanacetifolia'' File:Phacelia purshii - Miami Mist.jpg, '' Phacelia purshii''

References

External links

Panorama of a Phacelia Field
(QuickTime required) {{Authority control Boraginaceae genera Garden plants Flora of the Americas Taxa named by Antoine Laurent de Jussieu

Selected species

See also

References

Further reading

External links