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41-632: Heglig is the Arabic name of the "desert date", the fruit of the Balanites aegyptiaca tree, which is found in most parts of Africa and the Middle East. Sudanese Sufis use heglig ( lalob ) seeds to make rosaries. Lalob is also a favorite food for camels, goats, sheep and cattle. South Sudan does not recognize the name Heglig for the town. During the 10-day occupation by the SPLA, South Sudan restored

82-568: A negative complex. Plant phytohormones have an effect on the growth and response of plants to environmental stimuli. Some of these phytohormones are involved in trichome formation, which include gibberellic acid (GA), cytokinins (CK), and jasmonic acids (JA). GA stimulates growth of trichomes by stimulating GLABROUS1 (GL1); however, both SPINDLY and DELLA proteins repress the effects of GA, so less of these proteins create more trichomes. Some other phytohormones that promote growth of trichomes include brassinosteroids, ethylene, and salicylic acid. This

123-501: A persistent sticky network that helps maintain soil structure. Plant trichomes have many different features that vary between both species of plants and organs of an individual plant. These features affect the subcategories that trichomes are placed into. Some defining features include the following: In a model organism, Cistus salviifolius , there are more adaxial trichomes present on this plant because this surface suffers from more ultraviolet (UV), solar irradiance light stress than

164-691: A plant is an indumentum , and the surface bearing them is said to be pubescent . Certain, usually filamentous, algae have the terminal cell produced into an elongate hair-like structure called a trichome. The same term is applied to such structures in some cyanobacteria , such as Spirulina and Oscillatoria . The trichomes of cyanobacteria may be unsheathed, as in Oscillatoria , or sheathed, as in Calothrix . These structures play an important role in preventing soil erosion , particularly in cold desert climates . The filamentous sheaths form

205-451: A single cell of the epidermal layer. Root hairs form from trichoblasts , the hair-forming cells on the epidermis of a plant root . Root hairs vary between 5 and 17 micrometers in diameter, and 80 to 1,500 micrometers in length (Dittmar, cited in Esau, 1965). Root hairs can survive for two to three weeks and then die off. At the same time new root hairs are continually being formed at the top of

246-453: Is grown for its fruit in plantations in several areas. The bark yields fibers , the natural gums from the branches are used as glue , and the seeds have been used to make jewelry and beads . Various Sahel tribes use the thorn of the tree to make incisions that result in tattoos . The generic part of the binomial Balanites derives from the Greek word for an acorn and refers to

287-904: Is known as lalob , hidjihi , inteishit , and heglig ( hijlij ). In Jieng it is called Thou or thau , in Hausa it is called aduwa, in Tamasheq, the Tuareg language taboraq , in Fulfulde (Pulaar) Murtooki or Tanni , in Swahili mchunju , in Kamba Kilului and in Amharic bedena . The Balanites aegyptiaca tree reaches 10 m (33 ft) in height with a generally narrow form. The branches have long, straight green spines arranged in spirals. The dark green compound leaves grow out of

328-453: Is likely that in many cases, hairs interfere with the feeding of at least some small herbivores and, depending upon stiffness and irritability to the palate , large herbivores as well. Hairs on plants growing in areas subject to frost keep the frost away from the living surface cells. In windy locations, hairs break up the flow of air across the plant surface, reducing transpiration . Dense coatings of hairs reflect sunlight , protecting

369-458: Is the scale or peltate hair , that has a plate or shield-shaped cluster of cells attached directly to the surface or borne on a stalk of some kind. Common examples are the leaf scales of bromeliads such as the pineapple , Rhododendron and sea buckthorn ( Hippophae rhamnoides ). Any of the various types of hairs may be glandular , producing some kind of secretion, such as the essential oils produced by mints and many other members of

410-631: Is the result of deterring herbivores (Brookes et al. 2016). However, some organisms have developed mechanisms to resist the effects of trichomes. The larvae of Heliconius charithonia , for example, are able to physically free themselves from trichomes, are able to bite off trichomes, and are able to form silk blankets in order to navigate the leaves better. Stinging trichomes vary in their morphology and distribution between species, however similar effects on large herbivores implies they serve similar functions. In areas susceptible to herbivory, higher densities of stinging trichomes were observed. In Urtica ,

451-782: The Egyptian balsam and Lalob in Sudan ) is a species of tree , classified as a member of either the Zygophyllaceae or the Balanitaceae. This tree is native to much of Africa and parts of the Middle East . There are many common names for this plant. In English , the fruit has been called desert date, and the tree soap berry tree or bush, Thorn tree, Egyptian myrobalan, Egyptian balsam or Zachum oil tree; in Arabic it

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492-747: The Sahel-Savannah region across Africa and the Arabian Peninsula (within the countries of Lebanon, Libya, Syria, Oman, Palestine, Saudi Arabia and Yemen). It can be found in many kinds of habitat, tolerating a wide variety of soil types, from sand to heavy clay , and climatic moisture levels, from arid to subhumid. It is relatively tolerant of flooding, livestock activity, and wildfire . Balanites aegyptiaca has been cultivated in Egypt for more than 4000 years, and stones placed in tombs as votive offerings have been found as far back as

533-544: The Twelfth Dynasty . The tree was described in 1592 by Prospero Alpini under the name 'agihalid'. Linnaeus regarded it as a species of Ximenia , but Michel Adanson proposed the new genus of Agialid . The genus Balanites was founded in 1813 by Delile . The yellow, single- seeded fruit is edible, but bitter . Many parts of the plant are used as famine foods in Africa; the leaves are eaten raw or cooked,

574-479: The trichomes. Although trichomes are rarely found preserved in fossils , trichome bases are regularly found and, in some cases, their cellular structure is important for identification. Arabidopsis thaliana trichomes are classified as being aerial, epidermal, unicellular, tubular structures. In the model plant Arabidopsis thaliana , trichome formation is initiated by the GLABROUS1 protein. Knockouts of

615-759: The Government of South Sudan, emphasizing that the PCA established that Heglig was part of the north. The document of the PCA only indicated that the Heglig or Panthou area is not part of Abyei. There was fighting in the area during the 2012 Heglig Crisis , both the First Battle of Heglig and Second Battle of Heglig . Heglig Airport hosts three Sudanese Air Force helicopter squadrons ( Mil Mi-8 / Mil Mi-17 ). The airport's runways are both gravel. Balanites aegyptiaca Balanites aegyptiaca (also known as

656-467: The abaxial surface. Trichomes can protect the plant from a large range of detriments, such as UV light, insects, transpiration , and freeze intolerance. Trichomes on plants are epidermal outgrowths of various kinds. The terms emergences or prickles refer to outgrowths that involve more than the epidermis. This distinction is not always easily applied (see Wait-a-minute tree ). Also, there are nontrichomatous epidermal cells that protrude from

697-498: The ability to synthesize and store polyphenols that both affect absorbance of radiation and plant desiccation. These trichomes also contain acetylated flavonoids, which can absorb UV-B, and non-acetylated flavonoids, which absorb the longer wavelength of UV-A. In non-glandular trichomes, the only known role of flavonoids is to block out the shortest wavelengths to protect the plant; this differs from their role in glandular trichomes. In Salix and gossypium genus, modified trichomes create

738-529: The bark is also used as an abortifacient and an antidote for arrow poison in West African traditional medicine. The antigiardial (combating Giardia parasites), antiamoebic , antimicrobial , antioxidant activity and cytotoxicity of the fruits extract has been studied. The seed contains 30-48% fixed (non-volatile) oil , like the leaves, fruit pulp, bark and roots, and contains the sapogenins diosgenin and yamogenin . Saponins likewise occur in

779-556: The base of the spines and are made up of two leaflets which are variable in size and shape. The fluted trunk has grayish-brown, ragged bark with yellow-green patches where it is shed. The inflorescence consists of bunches of a few flowers which are either sessile or are borne on short stalks. The flower buds are ovoid and covered in a short tomentose pubescence. The individual flowers are greenish-yellow in colour, hermaphroditic with five petals in radial symmetry and are 8–14 millimetres (0.31–0.55 in) in diameter. The pedicel of

820-708: The bean leaves capture the insects by impaling their feet ( tarsi ). The leaves would then be destroyed. Trichomes are an essential part of nest building for the European wool carder bee ( Anthidium manicatum ). This bee species incorporates trichomes into their nests by scraping them off of plants and using them as a lining for their nest cavities. Plants may use trichomes in order to deter herbivore attacks via physical and/or chemical means, e.g. in specialized, stinging hairs of Urtica (Nettle) species that deliver inflammatory chemicals such as histamine . Studies on trichomes have been focused towards crop protection, which

861-496: The boundaries of Abyei , a county that lies between South Sudan and Sudan . The decision placed the Heglig and Bamboo oilfields out of Abyei boundary but did not specify to be belong to the Sudan province of South Kordofan , nor to Upper Nile region, South Sudan and also the decision did not specify oil sharing. The government of Sudan claimed that area is belong to its country since it was ruled to be out of Abyei boundary by PCA and announced they would not share any oil revenue with

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902-506: The corresponding gene lead to glabrous plants. This phenotype has already been used in genome editing experiments and might be of interest as visual marker for plant research to improve gene editing methods such as CRISPR/Cas9 . Trichomes also serve as models for cell differentiation as well as pattern formation in plants. Bean leaves have been used historically to trap bedbugs in houses in Eastern Europe . The trichomes on

943-465: The cottony fibers that allow anemochory , or wind aided dispersal. These seed trichomes are among the longest plant cells Non-glandular trichomes in the genus Cistus were found to contain presences of ellagitannins, glycosides , and kaempferol derivatives. The ellagitannins have the main purpose of helping adapt in times of nutrient-limiting stress. Both trichomes and root hairs , the rhizoids of many vascular plants , are lateral outgrowths of

984-455: The family Lamiaceae . Many terms are used to describe the surface appearance of plant organs, such as stems and leaves , referring to the presence, form and appearance of trichomes. Examples include: The size, form, density and location of hairs on plants are extremely variable in their presence across species and even within a species on different plant organs. Several basic functions or advantages of having surface hairs can be listed. It

1025-457: The fruit, this name was coined by Alire Delile in 1813. in Descr. Egypte, Hist. Nat. 221 1813 . The specific name aegyptiaca was applied by Carl Linnaeus as the species was initially described from specimens collected in Egypt. However, according to ICBN Art 62.4: "Generic names ending in -anthes, -oides or -odes are treated as feminine and those ending in -ites as masculine, irrespective of

1066-576: The gender assigned to them by the original author." Accordingly, the orthographic variant name that complies with ICBN Art 62.4 for this species is Balanites aegyptiacus . Tomentose Trichomes ( / ˈ t r aɪ k oʊ m z , ˈ t r ɪ k oʊ m z / ; from Ancient Greek τρίχωμα ( tríkhōma )  ' hair ') 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

1107-518: The inflorescence is greyish in colour, downy and usually less than 10 mm (0.39 in) in length, although 15 mm (0.59 in) has been recorded in Zambia and Zimbabwe . The ellipsoid fruit is normally less than 4 cm (1.6 in) long and is green when not ripe; it ripens to a brown or pale brown fruit with a crispy skin enclosing a sticky brown or brown-green pulp around a hard stone. The carpenter ant Camponotus sericeus feeds on

1148-537: The initiation and development of the epidermal outgrowth. Activation of genes that encode specific protein transcription factors (named GLABRA1 (GL1), GLABRA3 (GL3) and TRANSPARENT TESTA GLABRA1 (TTG1)) are the major regulators of cell fate to produce trichomes or root hairs. When these genes are activated in a leaf epidermal cell, the formation of a trichrome is initiated within that cell. GL1, GL3. and TTG1 also activate negative regulators, which serve to inhibit trichrome formation in neighboring cells. This system controls

1189-432: The model organism Arabidopsis thaliana , because their trichomes are simple, unicellular, and non-glandular. The development pathway is regulated by three transcription factors: R2R3 MYB , basic helix-loop-helix , and WD40 repeat . The three groups of TFs form a trimer complex (MBW) and activate the expression of products downstream, which activates trichome formation. However, just MYBs alone act as an inhibitor by forming

1230-408: The more delicate tissues underneath in hot, dry, open habitats. In addition, in locations where much of the available moisture comes from fog drip , hairs appear to enhance this process by increasing the surface area on which water droplets can accumulate. Glandular trichomes have been vastly studied, even though they are only found on about 30% of plants. Their function is to secrete metabolites for

1271-579: The name of the town Panthou, a Dinka translation of the word heglig . Panthou is a combination of two words in Dinka; "Pand" which mean the area or home and "Thou" which is the desert date tree, as such Panthou means land or home of desert's date. There are many places around the Dinka areas that have the name of Panthou. Heglig is situated within the Muglad Basin , a rift basin which contains much of South Sudan's proven oil reserves. The Heglig oil field

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1312-590: The nectar exuded by the flowers. The larva of the cabbage tree emperor moth Bunaea alcinoe causes defoliation of the tree. Balanites aegyptiaca is found in northern eastern Africa, (within the countries of Algeria, Angola, Benin, Botswana, Burkina, Burundi, Cameroon, Caprivi Strip, Central African Republic, Chad, Congo, Djibouti, Egypt, Eritrea, Ethiopia, Gambia, Ghana, Guinea-Bissau, Ivory Coast, Kenya, Malawi, Mali, Mauritania, Morocco, Mozambique, Niger, Nigeria, Rwanda, Senegal, Sinai, Somalia, Sudan, Tanzania, Togo, Uganda, Zambia, Zaïre and Zimbabwe) and including

1353-528: The oily seed is boiled to make it less bitter and eaten mixed with sorghum , and the flowers can be eaten. The tree is considered valuable in arid regions because it produces fruit even in dry times. The fruit can be fermented for alcoholic beverages . The seed cake remaining after the oil is extracted is commonly used as animal fodder in Africa. The seeds of the Balanites aegyptiaca have molluscicide effect on Biomphalaria pfeifferi . Where

1394-543: The plant. Some of these metabolites include: Non-glandular trichomes serve as structural protection against a variety of abiotic stressors, including water losses, extreme temperatures and UV radiation, and biotic threats, such as pathogen or herbivore attack. For example, the model plant C. salviifolius is found in areas of high-light stress and poor soil conditions, along the Mediterranean coasts. It contains non-glandular, stellate and dendritic trichomes that have

1435-420: The root. This way, the root hair coverage stays the same. It is therefore understandable that repotting must be done with care, because the root hairs are being pulled off for the most part. This is why planting out may cause plants to wilt. The genetic control of patterning of trichomes and roots hairs shares similar control mechanisms. Both processes involve a core of related transcription factors that control

1476-451: The roots, bark wood and fruit. The tree is managed through agroforestry . It is planted along irrigation canals and is used to attract insects for trapping. The pale to brownish yellow wood is used to make furniture and durable items such as tools, and is a low-smoke firewood that makes good charcoal . The smaller trees and branches are used as living or cut fences because they are resilient and thorny. The tree fixes nitrogen . It

1517-402: The spacing of trichomes on the leaf surface. Once trichome are developed they may divide or branch. In contrast, root hairs only rarely branch. During the formation of trichomes and root hairs, many enzymes are regulated. For example, just prior to the root hair development, there is a point of elevated phosphorylase activity. Many of what scientists know about trichome development comes from

1558-514: The species coexist, African elephants consume the desert date. Desert date fruit is mixed into porridge and eaten by nursing mothers, and the oil is consumed for headache and to improve lactation . Bark extracts and the fruit repel, or destroy, freshwater snails and copepods , organisms that act as intermediary hosts of parasites including Schistosoma , Bilharzia , and guinea worm . Worm infections are likewise treated with desert date, as are liver and spleen disorders. A decoction of

1599-467: The surface, such as root hairs . A common type of trichome is a hair . Plant hairs may be unicellular or multicellular , and branched or unbranched. Multicellular hairs may have one or several layers of cells. Branched hairs can be dendritic (tree-like) as in kangaroo paw ( Anigozanthos ), tufted , or stellate (star-shaped), as in Arabidopsis thaliana . Another common type of trichome

1640-603: Was first developed in 1996 by Arakis Energy (now part of Talisman Energy ). Today it is operated by the Greater Nile Petroleum Operating Company . Production at Heglig is reported to have peaked in 2006 and is now in decline. The Heglig oil field is connected to Khartoum and Port Sudan via the Greater Nile Oil Pipeline . In July 2009, the international organization, Permanent Court of Arbitration (PCA) redefined

1681-492: Was understood by conducting experiments with mutants that have little to no amounts of each of these substances. In every case, there was less trichome formation on both plant surfaces, as well as incorrect formation of the trichomes present. The type, presence and absence and location of trichomes are important diagnostic characters in plant identification and plant taxonomy. In forensic examination, plants such as Cannabis sativa can be identified by microscopic examination of

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