Halothamnus
Encyclopedia
Halothamnus is a genus of the former Chenopodiaceae
that is now included into the family Amaranthaceae
. The scientific name means saltbush, from the Greek ἅλς (hals) "salt" and θαμνος (thamnos) "bush". This refers either to salty habitats or to the accumulation of salt in the plants.
s or sub-shrubs, two species are annual
s. The alternate leaves are sitting without basal narrowing at the branches. They are simple, entire, half-terete or flat and slightly fleshy (succulent).
The bisexual inconspicuous flowers are sitting solitary in the axil of a green bract
and two green bracteoles. The five free tepals are green with membranous margins above a transverse line and colourless below. Five stamens arise from a cup-like structure (hypogynous disc) at the base of the flower. One ovary
is formed by two carpels, with a thick pistil, and two stigma
s.
The one-seeded, horizontally flattened fruit keeps being enclosed by the hardening perianth
. Wings develop from the transverse zone at the outer side of the tepals. Below the wings, the peranth forms a thick and lignified tube with a widened base. Its bottom side has five pits arranged in a ring, surrounded by a rim. These fruit characteristics are essential for the genus Halothamnus.
The pollen
grains are nearly ball-shaped, 18-38 µm in diameter, with 12-29 pores scattered all over the surface (pantoporate), just like it is typically for the goosefoot-family. The species differ from each other in pollen diameter and number of pores, the southern species with the smallest and the northern species with the largest pollen grains.
). There are no observations for the other species, but they are considered to be pollinated by insects, too.
The fruits enclosed by the hardened perianth are dispersed by the wind (anemochory), lifted up by their wings up to 20 mm in diameter.
The distribution of the genus extends from the Caucasus mountains
and Kazakhstan
through Central Asia
, Southwest Asia
southward to Somalia
. The westernmost localities are at the Sinai Peninsula
, the easternmost in Dzungaria
in China
. Most species occur in Iran, Afghanistan
, and southern Central Asia. All species grow in dry habitats of desert
s and semideserts from 0–2800 m above sea-level. They live on rocky, clayish, or sandy soils; many species tolerate saline conditions.
.
Some species of Halothamnus are important grazing plants for camels, sheep and goats, and are therefore used for the recultivation of pasture, for example Halothamnus subaphyllus, Halothamnus auriculus and Halothamnus glaucus. Halothamnus subaphyllus is planted for the stabilisation of mobile sands and for the production of the medically used alkaloid
Salsolin. Halothamnus somalensis is used as medicinal plant against parasitic worms.
In former times Halothamnus subaphyllus and Halothamnus glaucus were used to extract potash
for making soap.
within the family Amaranthaceae
, (formerly Chenopodiaceae
). It is grouped to Tribus Salsoleae, Subtribus Sodinae, and is closely related to genus Salsola
.
Type of the genus: Halothamnus bottae Jaub & Spach, Ill. Pl. Or. 2:50, tab. 136, 1845.
Synonyms:
The genus is classified into 2 sections with 21 species:
Sect. Pungentifolia Kothe-Heinr.
Sect. Halothamnus
Chenopodiaceae
Chenopodiaceae were a family of flowering plants, also called the Goosefoot Family. They are now included within family Amaranthaceae. The vast majority of Chenopods are weeds, and many are salt and drought tolerant. A few food crops also belong to the family: spinach, beets, chard, quinoa, and...
that is now included into the family Amaranthaceae
Amaranthaceae
The flowering plant family Amaranthaceae, the Amaranth family, contains about 176 genera and 2,400 species.- Description :Most of these species are herbs or subshrubs; very few are trees or climbers. Some species are succulent....
. The scientific name means saltbush, from the Greek ἅλς (hals) "salt" and θαμνος (thamnos) "bush". This refers either to salty habitats or to the accumulation of salt in the plants.
Description
Most species of Halothamnus are small shrubShrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s or sub-shrubs, two species are annual
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
s. The alternate leaves are sitting without basal narrowing at the branches. They are simple, entire, half-terete or flat and slightly fleshy (succulent).
The bisexual inconspicuous flowers are sitting solitary in the axil of a green bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
and two green bracteoles. The five free tepals are green with membranous margins above a transverse line and colourless below. Five stamens arise from a cup-like structure (hypogynous disc) at the base of the flower. One ovary
Ovary
The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in anatomically female individuals are analogous to testes in anatomically male individuals, in that they are both gonads and endocrine glands.-Human anatomy:Ovaries...
is formed by two carpels, with a thick pistil, and two stigma
Stigma (botany)
The stigma is the receptive tip of a carpel, or of several fused carpels, in the gynoecium of a flower. The stigma receives pollen at pollination and it is on the stigma that the pollen grain germinates. The stigma is adapted to catch and trap pollen with various hairs, flaps, or sculpturings...
s.
The one-seeded, horizontally flattened fruit keeps being enclosed by the hardening perianth
Perianth
The term perianth has two similar but separate meanings in botany:* In flowering plants, the perianth are the outer, sterile whorls of a flower...
. Wings develop from the transverse zone at the outer side of the tepals. Below the wings, the peranth forms a thick and lignified tube with a widened base. Its bottom side has five pits arranged in a ring, surrounded by a rim. These fruit characteristics are essential for the genus Halothamnus.
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
grains are nearly ball-shaped, 18-38 µm in diameter, with 12-29 pores scattered all over the surface (pantoporate), just like it is typically for the goosefoot-family. The species differ from each other in pollen diameter and number of pores, the southern species with the smallest and the northern species with the largest pollen grains.
Pollination and dissemination
In all species the stamens blossom first, and the stigmas unfold later (protandry). Halothamnus subaphyllus was proved to be pollinated by insects (entomophilyEntomophily
Entomophily is a form of pollination whereby pollen is distributed by insects. Several insect are reported to be responsible for the pollination of many plant species, particularly bees, Lepidoptera , wasps, flies, ants and beetles. Some plant species co-evolved with a particular pollinator, such...
). There are no observations for the other species, but they are considered to be pollinated by insects, too.
The fruits enclosed by the hardened perianth are dispersed by the wind (anemochory), lifted up by their wings up to 20 mm in diameter.
Distribution
Caucasus Mountains
The Caucasus Mountains is a mountain system in Eurasia between the Black Sea and the Caspian Sea in the Caucasus region .The Caucasus Mountains includes:* the Greater Caucasus Mountain Range and* the Lesser Caucasus Mountains....
and Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
through Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
, Southwest Asia
Southwest Asia
Western Asia, West Asia, Southwest Asia or Southwestern Asia are terms that describe the westernmost portion of Asia. The terms are partly coterminous with the Middle East, which describes a geographical position in relation to Western Europe rather than its location within Asia...
southward to Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
. The westernmost localities are at the Sinai Peninsula
Sinai Peninsula
The Sinai Peninsula or Sinai is a triangular peninsula in Egypt about in area. It is situated between the Mediterranean Sea to the north, and the Red Sea to the south, and is the only part of Egyptian territory located in Asia as opposed to Africa, effectively serving as a land bridge between two...
, the easternmost in Dzungaria
Dzungaria
Dzungaria, also called Zungaria, is a geographical region in northwest China corresponding to the northern half of Xinjiang. It covers approximately , lying mostly within Xinjiang, and extending into western Mongolia and eastern Kazakhstan...
in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. Most species occur in Iran, Afghanistan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...
, and southern Central Asia. All species grow in dry habitats of desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
s and semideserts from 0–2800 m above sea-level. They live on rocky, clayish, or sandy soils; many species tolerate saline conditions.
Photosynthesis pathway
All species of Halothamnus show leaf anatomy with Kranz arrangement of the Salsola-type. Physiological investigations confirmed that they are all C4-plantsC4 carbon fixation
C4 carbon fixation is one of three biochemical mechanisms, along with and CAM photosynthesis, used in carbon fixation. It is named for the 4-carbon molecule present in the first product of carbon fixation in these plants, in contrast to the 3-carbon molecule products in plants. fixation is an...
.
Economic importance
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
Salsolin. Halothamnus somalensis is used as medicinal plant against parasitic worms.
In former times Halothamnus subaphyllus and Halothamnus glaucus were used to extract potash
Potash
Potash is the common name for various mined and manufactured salts that contain potassium in water-soluble form. In some rare cases, potash can be formed with traces of organic materials such as plant remains, and this was the major historical source for it before the industrial era...
for making soap.
Systematics
The genus Halothamnus belongs to the subfamily SalsoloideaeSalsoloideae
The Salsoloideae is a subfamily of the Amaranthaceae, formerly in family Chenopodiaceae.- Description :These are herbs, subshrubs, shrubs and some trees. Stems and leaves are often succulent. The ovary contains a spiral embryo....
within the family Amaranthaceae
Amaranthaceae
The flowering plant family Amaranthaceae, the Amaranth family, contains about 176 genera and 2,400 species.- Description :Most of these species are herbs or subshrubs; very few are trees or climbers. Some species are succulent....
, (formerly Chenopodiaceae
Chenopodiaceae
Chenopodiaceae were a family of flowering plants, also called the Goosefoot Family. They are now included within family Amaranthaceae. The vast majority of Chenopods are weeds, and many are salt and drought tolerant. A few food crops also belong to the family: spinach, beets, chard, quinoa, and...
). It is grouped to Tribus Salsoleae, Subtribus Sodinae, and is closely related to genus Salsola
Salsola
Salsola is a genus of the subfamily Salsoloideae in the family Amaranthaceae. A common name of various members of this genus is saltwort, for its salt tolerance.-Description:...
.
Type of the genus: Halothamnus bottae Jaub & Spach, Ill. Pl. Or. 2:50, tab. 136, 1845.
Synonyms:
- Aellenia (Ulbr.) emend. Aellen
- SalsolaSalsolaSalsola is a genus of the subfamily Salsoloideae in the family Amaranthaceae. A common name of various members of this genus is saltwort, for its salt tolerance.-Description:...
L. sect. Sphragidanthus Iljin
The genus is classified into 2 sections with 21 species:
Sect. Pungentifolia Kothe-Heinr.
- Halothamnus beckettiiHalothamnus beckettiiHalothamnus beckettii is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, . It is the only member of the section H. sect.Pungentifolia, which differs from H. sect...
Botsch.
Sect. Halothamnus
- Halothamnus somalensisHalothamnus somalensisHalothamnus somalensis is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
(N.E.Br.) Botsch. - Halothamnus bottaeHalothamnus bottaeHalothamnus bottae is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
Jaub. & Spach - with 2 subspecies - Halothamnus iranicusHalothamnus iranicusHalothamnus iranicus is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
Botsch. - Halothamnus hierochunticusHalothamnus hierochunticusHalothamnus hierochunticus is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
(Bornm.) Botsch. - Halothamnus iliensisHalothamnus iliensisHalothamnus iliensis is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
(Lipsky) Botsch. - Halothamnus auriculusHalothamnus auriculusHalothamnus auriculus is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
(Moq.) Botsch. - with 2 subspecies - Halothamnus kermanensis Kothe-Heinr.
- Halothamnus afghanicus Kothe-Heinr.
- Halothamnus lancifoliusHalothamnus lancifoliusHalothamnus lancifolius is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
(Boiss.) Kothe-Heinr. - Halothamnus cinerascens (Moq.) Kothe-Heinr. - with 2 subspecies
- Halothamnus glaucusHalothamnus glaucusHalothamnus glaucus is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
(M.Bieb.) Botsch. - with 3 subspecies - Halothamnus bamianicus (Gilli) Botsch.
- Halothamnus schurobi (Botsch.)
- Halothamnus turcomanicus Botsch.
- Halothamnus ferganensis Botsch.
- Halothamnus sistanicus (De Marco & Dinelli) Kothe-Heinr.
- Halothamnus oxianus Botsch.
- Halothamnus seravschanicus Botsch.
- Halothamnus iraqensis Botsch.
- Halothamnus subaphyllusHalothamnus subaphyllusHalothamnus subaphyllus is a species of the plant genus Halothamnus, that is now included into the family Amaranthaceae, .- Morphology :...
(C.Meyer) Botsch. - with 3 subspecies
External links
- Schweizerbart Bibliotheca Botanica Bd. 143 Webpage
- http://ww2.bgbm.org/herbarium/Access.cfm?Col=4&IsoCode=all&Fam=CHENOPODIACEAE&SubColl=all&FullNameCache=all&Genus=Halothamnus Digital herbarium specimens from Herbarium Berlin
- Wikispecies: Halothamnus - species and subspecies, taxonomical information